High performance curable polymers and processes for the preparation thereof

ABSTRACT

Disclosed is a composition which comprises a polymer containing at least some monomer repeat units with photosensitivity-imparting substituents which enable crosslinking or chain extension of the polymer upon exposure to actinic radiation, said polymer being of the formula  
                 
 
     wherein x is an integer of 0 or 1, A is one of several specified groups, such as  
                 
 
     B is one of several specified groups, such as  
                 
 
     or mixtures thereof, and n is an integer representing the number of repeating monomer units, wherein said photosensitivity-imparting substituents are allyl ether groups, epoxy groups, or mixtures thereof. Also disclosed are a process for preparing a thermal ink jet printhead containing the aforementioned polymers and processes for preparing the aforementioned polymers.

BACKGROUND OF THE INVENTION

[0001] The present invention is directed to curable polymeric materials.More specifically, the present invention is directed to high performancepolymers with photosensitivity-imparting groups, processes for thepreparation thereof, and improved photoresist and improved thermal inkjet printheads containing these materials. One embodiment of the presentinvention is directed to a composition which comprises a polymercontaining at least some monomer repeat units withphotosensitivity-imparting substituents which enable crosslinking orchain extension of the polymer upon exposure to actinic radiation, saidpolymer being of the formula

[0002] wherein x is an integer of 0 or 1, A is

[0003] wherein v is an integer of from 1 to about 20,

[0004] wherein z is an integer of from 2 to about 20,

[0005] wherein u is an integer of from 1 to about 20,

[0006] wherein w is an integer of from 1 to about 20,

[0007] or mixtures thereof, and n is an integer representing the numberof repeating monomer units, wherein said photosensitivity-impartingsubstituents are allyl ether groups, epoxy groups, or mixtures thereof.Another embodiment of the present invention is directed to a processwhich comprises the steps of:

[0008] (a) depositing a layer comprising a polymer of the above formulaonto a lower substrate in which one surface thereof has an array ofheating elements and addressing electrodes having terminal ends formedthereon, said polymer being deposited onto the surface having theheating elements and addressing electrodes thereon;

[0009] (b) exposing the layer to actinic radiation in an imagewisepattern such that the polymer in exposed areas becomes crosslinked orchain extended and the polymer in unexposed areas does not becomecrosslinked or chain extended, wherein the unexposed areas correspond toareas of the lower substrate having thereon the heating elements and theterminal ends of the addressing electrodes;

[0010] (c) removing the polymer from the unexposed areas, therebyforming recesses in the layer, said recesses exposing the heatingelements and the terminal ends of the addressing electrodes;

[0011] (d) providing an upper substrate with a set of parallel groovesfor subsequent use as ink channels and a recess for subsequent use as amanifold, the grooves being open at one end for serving as dropletemitting nozzles; and

[0012] (e) aligning, mating, and bonding the upper and lower substratestogether to form a printhead with the grooves in the upper substratebeing aligned with the heating elements in the lower substrate to formdroplet emitting nozzles, thereby forming a thermal ink jet printhead.Yet other embodiments of the present invention are directed to processesfor preparing the aforementioned polymers.

[0013] In microelectronics applications, there is a great need for lowdielectric constant, high glass transition temperature, thermallystable, photopatternable polymers for use as interlayer dielectriclayers and as passivation layers which protect microelectroniccircuitry. Poly(imides) are widely used to satisfy these needs; thesematerials, however, have disadvantageous characteristics such asrelatively high water sorption and hydrolytic instability. There is thusa need for high performance polymers which can be effectivelyphotopatterned and developed at high resolution.

[0014] One particular application for such materials is the fabricationof ink jet printheads. Ink jet printing systems generally are of twotypes: continuous stream and drop-on-demand. In continuous stream inkjet systems, ink is emitted in a continuous stream under pressurethrough at least one orifice or nozzle. The stream is perturbed, causingit to break up into droplets at a fixed distance from the orifice. Atthe break-up point, the droplets are charged in accordance with digitaldata signals and passed through an electrostatic field which adjusts thetrajectory of each droplet in order to direct it to a gutter forrecirculation or a specific location on a recording medium. Indrop-on-demand systems, a droplet is expelled from an orifice directlyto a position on a recording medium in accordance with digital datasignals. A droplet is not formed or expelled unless it is to be placedon the recording medium.

[0015] Since drop-on-demand systems require no ink recovery, charging,or deflection, the system is much simpler than the continuous streamtype. There are different types of drop-on-demand ink jet systems. Onetype of drop-on-demand system has as its major components an ink filledchannel or passageway having a nozzle on one end and a piezoelectrictransducer near the other end to produce pressure pulses. The relativelylarge size of the transducer prevents close spacing of the nozzles, andphysical limitations of the transducer result in low ink drop velocity.Low drop velocity seriously diminishes tolerances for drop velocityvariation and directionality, thus impacting the system's ability toproduce high quality copies. Drop-on-demand systems which usepiezoelectric devices to expel the droplets also suffer the disadvantageof a slow printing speed.

[0016] The other type of drop-on-demand system is known as thermal inkjet, or bubble jet, and produces high velocity droplets and allows veryclose spacing of nozzles. The major components of this type ofdrop-on-demand system are an ink filled channel having a nozzle on oneend and a heat generating resistor near the nozzle. Printing signalsrepresenting digital information originate an electric current pulse ina resistive layer within each ink passageway near the orifice or nozzle,causing the ink in the immediate vicinity to vaporize almostinstantaneously and create a bubble. The ink at the orifice is forcedout as a propelled droplet as the bubble expands. When the hydrodynamicmotion of the ink stops, the process is ready to start all over again.With the introduction of a droplet ejection system based upon thermallygenerated bubbles, commonly referred to as the “bubble jet” system, thedrop-on-demand ink jet printers provide simpler, lower cost devices thantheir continuous stream counterparts, and yet have substantially thesame high speed printing capability.

[0017] The operating sequence of the bubble jet system begins with acurrent pulse through the resistive layer in the ink filled channel, theresistive layer being in close proximity to the orifice or nozzle forthat channel. Heat is transferred from the resistor to the ink. The inkbecomes superheated far above its normal boiling point, and for waterbased ink, finally reaches the critical temperature for bubble formationor nucleation of around 280° C. Once nucleated, the bubble or watervapor thermally isolates the ink from the heater and no further heat canbe applied to the ink. This bubble expands until all the heat stored inthe ink in excess of the normal boiling point diffuses away or is usedto convert liquid to vapor, which removes heat due to heat ofvaporization. The expansion of the bubble forces a droplet of ink out ofthe nozzle, and once the excess heat is removed, the bubble collapses.At this point, the resistor is no longer being heated because thecurrent pulse has passed and, concurrently with the bubble collapse, thedroplet is propelled at a high rate of speed in a direction towards arecording medium. The surface of the printhead encounters a severecavitational force by the collapse of the bubble, which tends to erodeit. Subsequently, the ink channel refills by capillary action. Thisentire bubble formation and collapse sequence occurs in about 10microseconds. The channel can be refired after 100 to 500 microsecondsminimum dwell time to enable the channel to be refilled and to enablethe dynamic refilling factors to become somewhat dampened. Thermal inkjet equipment and processes are well known and are described in, forexample, U.S. Pat. Nos. 4,601,777, 4,251,824, 4,410,899, 4,412,224,4,532,530, and 4,774,530, the disclosures of each of which are totallyincorporated herein by reference.

[0018] The present invention is suitable for ink jet printing processes,including drop-on-demand systems such as thermal ink jet printing,piezoelectric drop-on-demand printing, and the like.

[0019] In ink jet printing, a printhead is usually provided having oneor more ink-filled channels communicating with an ink supply chamber atone end and having an opening at the opposite end, referred to as anozzle. These printheads form images on a recording medium such as paperby expelling droplets of ink from the nozzles onto the recording medium.The ink forms a meniscus at each nozzle prior to being expelled in theform of a droplet. After a droplet is expelled, additional ink surges tothe nozzle to reform the meniscus.

[0020] In thermal ink jet printing, a thermal energy generator, usuallya resistor, is located in the channels near the nozzles a predetermineddistance therefrom. The resistors are individually addressed with acurrent pulse to momentarily vaporize the ink and form a bubble whichexpels an ink droplet. As the bubble grows, the ink bulges from thenozzle and is contained by the surface tension of the ink as a meniscus.The rapidly expanding vapor bubble pushes the column of ink filling thechannel towards the nozzle. At the end of the current pulse the heaterrapidly cools and the vapor bubble begins to collapse. However, becauseof inertia, most of the column of ink that received an impulse from theexploding bubble continues its forward motion and is ejected from thenozzle as an ink drop. As the bubble begins to collapse, the ink stillin the channel between the nozzle and bubble starts to move towards thecollapsing bubble, causing a volumetric contraction of the ink at thenozzle and resulting in the separation of the bulging ink as a droplet.The acceleration of the ink out of the nozzle while the bubble isgrowing provides the momentum and velocity of the droplet in asubstantially straight line direction towards a recording medium, suchas paper.

[0021] Ink jet printheads include an array of nozzles and may, forexample, be formed of silicon wafers using orientation dependent etching(ODE) techniques. The use of silicon wafers is advantageous because ODEtechniques can form structures, such as nozzles, on silicon wafers in ahighly precise manner. Moreover, these structures can be fabricatedefficiently at low cost. The resulting nozzles are generally triangularin cross-section. Thermal ink jet printheads made by using theabove-mentioned ODE techniques typically comprise a channel plate whichcontains a plurality of nozzle-defining channels located on a lowersurface thereof bonded to a heater plate having a plurality of resistiveheater elements formed on an upper surface thereof and arranged so thata heater element is located in each channel. The upper surface of theheater plate typically includes an insulative layer which is patternedto form recesses exposing the individual heating elements. Thisinsulative layer is referred to as a “pit layer” and is sandwichedbetween the channel plate and heater plate. For examples of printheadsemploying this construction, see U.S. Pat. Nos. 4,774,530 and 4,829,324,the disclosures of each of which are totally incorporated herein byreference. Additional examples of thermal ink jet printheads aredisclosed in, for example, U.S. Pat. Nos. 4,835,553, 5,057,853, and4,678,529, the disclosures of each of which are totally incorporatedherein by reference.

[0022] The photopatternable polymers prepared by the process of thepresent invention are also suitable for other photoresist applications,including other microelectronics applications, printed circuit boards,lithographic printing processes, interlayer dielectrics, and the like.

[0023] U.S. Pat. No. 3,914,194 (Smith), the disclosure of which istotally incorporated herein by reference, discloses a formaldehydecopolymer resin having dependent unsaturated groups with the repeatingunit

[0024] wherein R is an aliphatic acyl group derived from saturated acidshaving 2 to 6 carbons, olefinically unsaturated acids having 3 to 20carbons, or an omega-carboxy-aliphatic acyl group derived fromolefinically unsaturated dicarboxylic acids having 4 to 12 carbons ormixtures thereof, R₁ is independently hydrogen, an alkyl group of 1 to10 carbon atoms, or halogen, Z is selected from oxygen, sulfur, thegroup represented by Z taken with the dotted line representsdibenzofuran and dibenzothiophene moieties, or mixtures thereof, n is awhole number sufficient to give a weight average molecular weightgreater than about 500, m is 0 to 2, p and q have an average value of 0to 1 with the proviso that the total number of p and q groups aresufficient to give greater than one unsaturated group per resinmolecule. These resins are useful to prepare coatings on varioussubstrates or for potting electrical components by mixing with reactivediluents and curing agents and curing.

[0025] “Chloromethylation of Condensation Polymers Containing anoxy-1,4-phenylene Backbone,” W. H. Daly et al., Polymer Preprints, Vol.20, No. 1, 835 (1979), the disclosure of which is totally incorporatedherein by reference, discloses the chloromethylation of polymerscontaining oxy-phenylene repeat units to produce film forming resinswith high chemical reactivity. The utility of1,4-bis(chloromethoxy)butane and 1-chloromethoxy-4-chlorobutane aschloromethylating agents are also described.

[0026] European Patent Application EP-0,698,823-A1 (Fahey et al.), thedisclosure of which is totally incorporated herein by reference,discloses a copolymer of benzophenone and bisphenol A which was shown tohave deep ultraviolet absorption properties. The copolymer was founduseful as an antireflective coating in microlithography applications.Incorporating anthracene into the copolymer backbone enhanced absorptionat 248 nm. The encapper used for the copolymer varied depending on theneeds of the user and was selectable to promote adhesion, stability, andabsorption of different wavelengths.

[0027] M. Camps, M. Chatzopoulos, and J. Montheard, “ChloromethylStyrene: Synthesis, Polymerization, Transformations, Applications,”JMS—Rev. Macromol. Chem. Phys., C22(3), 343-407 (1982-3), the disclosureof which is totally incorporated herein by reference, disclosesprocesses for the preparation of chloromethyl-substituted polystyrenes,as well as applications thereof.

[0028] Y. Tabata, S. Tagawa, and M. Washio, “Pulse Radiolysis Studies onthe Mechanism of the High Sensitivity of Chloromethylated Polystyrene asan Electron Negative Resist,” Lithography, 25(1), 287 (1984), thedisclosure of which is totally incorporated herein by reference,discloses the use of chloromethylated polystyrene in resistapplications.

[0029] M. J. Jurek, A. E. Novembre, I. P. Heyward, R. Gooden, and E.Reichmanis, “Deep UV Photochemistry of Copolymers ofTrimethyl-Silylmethyl Methacrylate and Chloromethylstyrene,” PolymerPreprints, 29(1) (1988), the disclosure of which is totally incorporatedherein by reference, discloses the use of an organosilicon polymer ofchloromethylstyrene for resist applications.

[0030] P. M. Hergenrother, B. J. Jensen, and S. J. Havens, “Poly(aryleneethers),” Polymer, 29, 358 (1988), the disclosure of which is totallyincorporated herein by reference, discloses several arylene etherhomopolymers and copolymers prepared by the nucleophilic displacement ofaromatic dihalides with aromatic potassium bisphenates. Polymer glasstransition temperatures ranged from 114 to 310° C. and some weresemicrystalline. Two ethynyl-terminated polyarylene ethers) weresynthesized by reacting hydroxy-terminated oligomers with4-ethynylbenzoyl chloride. Heat induced reaction of the acetylenicgroups provided materials with good solvent resistance. The chemistry,physical, and mechanical properties of the polymers are also disclosed.

[0031] S. J. Havens, “Ethynyl-Terminated Polyarylates: Synthesis andCharacterization,” Journal of Polymer Science: Polymer ChemistryEdition, vol. 22, 3011-3025 (1984), the disclosure of which is totallyincorporated herein by reference, discloses hydroxy-terminatedpolyarylates with number average molecular weights of about 2500, 5000,7500, and 10,000 which were synthesized and converted to corresponding4-ethynylbenzoyloxy-terminated polyarylates by reaction with4-ethynylbenzoyl chloride. The terminal ethynyl groups were thermallyreacted to provide chain extension and crosslinking. The cured polymerexhibited higher glass transition temperatures and better solventresistance than a high molecular weight linear polyarylate. Solventresistance was further improved by curing2,2-bis(4-ethynylbenzoyloxy-4′-phenyl)propane, a coreactant, with theethynyl-terminated polymer at concentrations of about 10 percent byweight.

[0032] N. H. Hendricks and K. S. Y. Lau, “Flare, a Low DielectricConstant, High Tg, Thermally Stable Poly(arylene ether) Dielectric forMicroelectronic Circuit Interconnect Process Integration: Synthesis,Characterization, Thermomechanical Properties, and Thin-Film ProcessingStudies,” Polymer Preprints, 37(1), 150 (1996), the disclosure of whichis totally incorporated herein by reference, discloses non-carbonylcontaining aromatic polyethers such as fluorinated poly(arylene ethers)based on decafluorobiphenyl as a class of intermetal dielectrics forapplications in sub-half micron multilevel interconnects.

[0033] J. J. Zupancic, D. C. Blazej, T. C. Baker, and E. A. Dinkel,“Styrene Terminated Resins as Interlevel Dielectrics for MultichipModels,” Polymer Preprints, 32, (2), 178 (1991), the disclosure of whichis totally incorporated herein by reference, discloses vinylbenzylethers of polyphenols (styrene terminated resins) which were found to bephotochemically and thermally labile, generating highly crosslinkednetworks. The resins were found to yield no volatile by-products duringthe curing process and high glass transition, low dielectric constantcoatings. One of the resins was found to be spin coatable to varyingthickness coatings which could be photodefined, solvent developed, andthen hard baked to yield an interlevel dielectric.

[0034] Japanese Patent Kokai JP 04294148-A, the disclosure of which istotally incorporated herein by reference, discloses a liquid injectingrecording head containing the cured matter of a photopolymerizablecomposition comprising (1) a graft polymer comprising (A) alkylmethacrylate, acrylonitrile, and/or styrene as the trunk chain and an—OH group-containing acryl monomer, (B) amino or alkylaminogroup-containing acryl monomer, (C) carboxyl group-containing acryl orvinyl monomers, (D) N-vinyl pyrrolidone, vinyl pyridine or itsderivatives, and/or (F) an acrylamide as the side chain; (2) a linearpolymer containing constitutional units derived from methylmethacrylate, ethyl methacrylate, isobutyl methacrylate, t-butylmethacrylate, benzyl methacrylate, acrylonitrile, isobornylmethacrylate, tricyclodecane acrylate, tricyclodecane oxyethylmethacrylate, styrene, dimethylaminoethyl methacrylate, and/orcyclohexyl methacrylate, and constitutional unit derived from the abovecompounds (A), (B), (C), (D), (E), or (F) above; (3) an ethylenicunsaturated bond containing monomer; and (4) a photopolymerizationinitiator which contains (a) an organic peroxide, s-triazine derivative,benzophenone or its derivatives, quinones, N-phenylglycine, and/oralkylarylketones as a radical generator and (b) coumarin dyes,ketocoumarin dyes, cyanine dyes, merocyanine dyes, and/or xanthene dyesas a sensitizer.

[0035] “Functional Polymers and Sequential Copolymers by Phase TransferCatalysis, 2a: Synthesis and Characterization of Aromatic Poly(ethersulfone)s Containing Vinylbenzyl and Ethynylbenzyl Chain Ends,” V.Percec and B. C. Auman, Makromol. Chem., 185, 1867-1880 (1984), thedisclosure of which is totally incorporated herein by reference,discloses a method for the synthesis of α,ω-bis(vinylbenzyl) aromaticpoly(ether sulfone)s and their transformation intoα,ω-bis(ethynylbenzyl) aromatic poly(ether sulfone)s. The method entailsa fast and quantitative Williamson etherification of theα,ω-bis(hydroxyphenyl)polysulfone with a mixture of p- andm-chloromethylstyrenes in the presence of tetrabutylammonium hydrogensulfate as phase transfer catalyst, a subsequent bromination, and then adehydrobromination with potassium tert-butoxide. The DSC study of thethermal curing of the α,ω-bis(vinylbenzyl) aromatic poly(ether sulfone)sand α,ω-bis(ethynylbenzyl) aromatic poly(ether sulfone)s demonstrateshigh thermal reactivity for the styrene-terminated oligomers.

[0036] “Functional Polymers and Sequential Copolymers by Phase TransferCatalysis, 3a: Synthesis and Characterization of Aromatic Poly(ethersulfone)s and Poly(oxy-2,6-dimethyl-1,4-phenylene) Containing PendentVinyl Groups,” V. Percec and B. C. Auman, Makromol. Chem., 185,2319-2336 (1984), the disclosure of which is totally incorporated hereinby reference, discloses a method for the syntheses of α,ω-benzylaromatic poly(ether sulfone)s (PSU) andpoly(oxy-2,6-dimethyl-1,4-phenylene) (POP) containing pendant vinylgroups. The first step of the synthetic procedure entails thechloromethylation of PSU and POP to provide polymers with chloromethylgroups. POP, containing bromomethyl groups, was obtained by radicalbromination of the methyl groups. Both chloromethylated andbromomethylated starting materials were transformed into theirphosphonium salts, and then subjected to a phase transfer catalyzedWittig reaction to provide polymers with pendant vinyl groups. A PSUwith pendant ethynyl groups was prepared by bromination of the PSUcontaining vinyl groups, followed by a phase transfer catalyzeddehydrobromination. DSC of the thermal curing of the polymers containingpendant vinyl and ethynyl groups showed that the curing reaction is muchfaster for the polymers containing vinyl groups. The resulting networkpolymers are flexible when the starting polymer contains vinyl groups,and very rigid when the starting polymer contains ethynyl groups.

[0037] “Functional Polymers and Sequential Copolymers by Phase TransferCatalysis,” V. Percec and P. L. Rinaldi, Polymer Bulletin, 10, 223(1983), the disclosure of which is totally incorporated herein byreference, discloses the preparation of p- andm-hydroxymethylphenylacetylenes by a two step sequence starting from acommercial mixture of p- and m-chloromethylstyrene, i.e., by thebromination of the vinylic monomer mixture followed by separation of m-and p-brominated derivatives by fractional crystallization, andsimultaneous dehydrobromination and nucleophilic substitution of the —Clwith —OH.

[0038] U.S. Pat. No. 4,110,279 (Nelson et al.), the disclosure of whichis totally incorporated herein by reference, discloses a polymer derivedby heating in the presence of an acid catalyst at between about 65° C.and about 250° C.: I. a reaction product, a cogeneric mixture of alkoxyfunctional compounds, having average equivalent weights in the range offrom about 220 to about 1200, obtained by heating in the presence of astrong acid at about 50° C. to about 250° C.: (A) a diaryl compoundselected from naphthalene, diphenyl oxide, diphenyl sulfide, theiralkylated or halogenated derivatives, or mixtures thereof, (B)formaldehyde or formaldehyde yielding derivative, (C) water, and (D) ahydroxy aliphatic hydrocarbon compound having at least one free hydroxylgroup and from 1 to 4 carbon atoms, which mixture contains up to 50percent unreacted (A); with II. at least one monomeric phenolic reactantselected from the group

[0039] wherein R is selected from the group consisting of hydrogen,alkyl radical of 1 to 20 carbon atoms, aryl radical of 6 to 20 carbonatoms, wherein R₁ represents hydrogen, alkyl, or aryl, m represents aninteger from 1 to 3, o represents an integer from 1 to 5, p representsan integer from 0 to 3, X represents oxygen, sulfur, or alkylidene, andq represents an integer from 0 to 1; and III. optionally an aldehyde oraldehyde-yielding derivative or ketone, for from several minutes toseveral hours. The polymeric materials are liquids or low melting solidswhich are capable of further modification to thermoset resins. Thesepolymers are capable of being thermoset by heating at a temperature offrom about 130° C. to about 260° C. for from several minutes to severalhours in the presence of a formaldehyde-yielding compound. Thesepolymers are also capable of further modification by reacting underbasic conditions with formaldehyde with or without a phenolic compound.The polymers, both base catalyzed resoles and acid catalyzed novolacs,are useful as laminating, molding, film-forming, and adhesive materials.The polymers, both resoles and novolacs, can be epoxidized as well asreacted with a drying oil to produce a varnish resin.

[0040] U.S. Pat. No. 3,367,914 (Herbert), the disclosure of which istotally incorporated herein by reference, discloses thermosettingresinous materials having melting points in the range of from 150° C. to350° C. which are made heating at a temperature of from −10° C. to 100°C. for 5 to 30 minutes an aldehyde such as formaldehyde or acetaldehydewith a mixture of poly(aminomethyl) diphenyl ethers having an average offrom about 1.5 to 4.0 aminomethyl groups. After the resins are curedunder pressure at or above the melting point, they form adherent toughfilms on metal substrates and thus are useful as wire coatings forelectrical magnet wire for high temperature service at 180° C. orhigher.

[0041] J. S. Amato, S. Karady, M. Sletzinger, and L. M. Weinstock, “ANew Preparation of Chloromethyl Methyl Ether Free of Bis(chloromethyl)Ether,” Synthesis, 970 (1979), the disclosure of which is totallyincorporated herein by reference, discloses the synthesis ofchloromethyl methyl ether by the addition of acetyl chloride to a slightexcess of anhydrous dimethoxymethane containing a catalytic amount ofmethanol at room temperature. The methanol triggers a series ofreactions commencing with formation of hydrogen chloride and thereaction of hydrogen chloride with dimethoxymethane to form chloromethylmethyl ether and methanol in an equilibrium process. After 36 hours, anear-quantitative conversion to an equimolar mixture of chloromethylmethyl ether and methyl acetate is obtained.

[0042] A. McKillop, F. A. Madjdabadi, and D. A. Long, “A Simple andInexpensive Procedure for Chloromethylation of Certain AromaticCompounds,” Tetrahedron Letters, Vol. 24, No. 18, pp. 1933-1936 (1983),the disclosure of which is totally incorporated herein by reference,discloses the reaction of a range of aromatic compounds withmethoxyacetyl chloride and aluminum chloride in either nitromethane orcarbon disulfide to result in chloromethylation in good to excellentyield.

[0043] E. P. Tepenitsyna, M. I. Farberov, and A. P. Ivanovskii,“Synthesis of Intermediates for Production of Heat Resistant Polymers(Chloromethylation of Diphenyl Oxide),” Zhurnal Prikladnoi Khimii, Vol.40, No. 11, pp. 2540-2546 (1967), the disclosure of which is totallyincorporated herein by reference, discloses the chloromethylation ofdiphenyl oxide by (1) the action of paraformaldehyde solution in glacialacetic acid saturated with hydrogen chloride, and by (2) the action ofparaformaldehyde solution in concentrated hydrochloric acid.

[0044] U.S. Pat. No. 2,125,968 (Theimer), the disclosure of which istotally incorporated herein by reference, discloses the manufacture ofaromatic alcohols by the Friedel-Crafts reaction, in which an alkyleneoxide is condensed with a Friedel-Crafts reactant in the presence of ananhydrous metal halide.

[0045] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/95171), filed concurrently herewith, entitled “Thermal InkJet Printhead With Ink Resistant Heat Sink Coating,” with the namedinventors Ram S. Narang and Timothy J. Fuller, the disclosure of whichis totally incorporated herein by reference, discloses a heat sink for athermal ink jet printhead having improved resistance to the corrosiveeffects of ink by coating the surface of the heat sink with an inkresistant film formed by electrophoretically depositing a polymericmaterial on the heat sink surface. In one described embodiment, athermal ink jet printer is formed by bonding together a channel plateand a heater plate. Resistors and electrical connections are formed inthe surface of the heater plate. The heater plate is bonded to a heatsink comprising a zinc substrate having an electrophoretically depositedpolymeric film coating. The film coating provides resistance to thecorrosion of higher pH inks. In another embodiment, the coating hasconductive fillers dispersed therethrough to enhance the thermalconductivity of the heat sink. In one embodiment, the polymeric materialis selected from the group consisting of polyethersulfones,polysulfones, polyamides, polyimides, polyamide-imides, epoxy resins,polyetherimides, polyarylene ether ketones, chloromethylated polyaryleneether ketones, acryloylated polyarylene ether ketones, polystyrene andmixtures thereof.

[0046] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/95173), filed concurrently herewith, entitled “Method forApplying an Adhesive Layer to a Substrate Surface,” with the namedinventors Ram S. Narang, Stephen F. Pond, and Timothy J. Fuller, thedisclosure of which is totally incorporated herein by reference,discloses a method for uniformly coating portions of the surface of asubstrate which is to be bonded to another substrate. In a describedembodiment, the two substrates are channel plates and heater plateswhich, when bonded together, form a thermal ink jet printhead. Theadhesive layer is electrophoretically deposited over a conductivepattern which has been formed on the binding substrate surface. Theconductive pattern forms an electrode and is placed in anelectrophoretic bath comprising a colloidal emulsion of a preselectedpolymer adhesive. The other electrode is a metal container in which thesolution is placed or a conductive mesh placed within the container. Theelectrodes are connected across a voltage source and a field is applied.The substrate is placed in contact with the solution, and a smallcurrent flow is carefully controlled to create an extremely uniform thindeposition of charged adhesive micelles on the surface of the conductivepattern. The substrate is then removed and can be bonded to a secondsubstrate and cured. In one embodiment, the polymer adhesive is selectedfrom the group consisting of polyamides, polyimides, polyamide-imides,epoxy resins, polyetherimides, polysulfones, polyether sulfones,polyarylene ether ketones, polystyrenes, chloromethylated polyaryleneether ketones, acryloylated plyarylene ether ketones, and mixturesthereof.

[0047] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/95174), filed concurrently herewith, entitled“Electrophoretically Deposited Coating For the Front Face of an Ink JetPrinthead,” with the named inventors Ram S. Narang, Stephen F. Pond, andTimothy J. Fuller, the disclosure of which is totally incorporatedherein by reference, discloses an electrophoretic deposition techniquefor improving the hydrophobicity of a metal surface, in one embodiment,the front face of a thermal ink jet printhead. For this example, a thinmetal layer is first deposited on the front face. The front face is thenlowered into a colloidal bath formed by a fluorocarbon-doped organicsystem dissolved in a solvent and then dispersed in a non-solvent. Anelectric field is created and a small amount of current through the bathcauses negatively charged particles to be deposited on the surface ofthe metal coating. By controlling the deposition time and currentstrength, a very uniform coating of the fluorocarbon compound is formedon the metal coating. The electrophoretic coating process is conductedat room temperature and enables a precisely controlled deposition whichis limited only to the front face without intrusion into the front faceorifices. In one embodiment, the organic compound is selected from thegroup consisting of polyimides, polyamides, polyamide-imides,polysulfones, polyarylene ether ketones, polyethersulfones,polytetrafluoroethylenes, polyvinylidene fluorides,polyhexafluoro-propylenes, epoxies, polypentafluorostyrenes,polystyrenes, copolymers thereof, terpolymers thereof, and mixturesthereof.

[0048] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/95176), filed concurrently herewith, entitled “StabilizedGraphite Substrates,” with the named inventors Gary A. Kneezel, Ram S.Narang, Timothy J. Fuller, and Peter J. John, the disclosure of which istotally incorporated herein by reference, discloses an apparatus whichcomprises at least one semiconductor chip mounted on a substrate, saidsubstrate comprising a graphite member having electrophoreticallydeposited thereon a coating of a polymeric material. In one embodiment,the semiconductor chips are thermal ink jet printhead subunits. In oneembodiment, the polymeric material is of the general formula

[0049] wherein x is an integer of 0 or 1, A is one of several specifiedgroups, such as

[0050] B is one of several specified groups, such as

[0051] or mixtures thereof, and n is an integer representing the numberof repeating monomer units.

[0052] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/95635), filed concurrently herewith, entitled “ImprovedCurable Compositions,” with the named inventors Timothy J. Fuller, RamS. Narang, Thomas W. Smith, David J. Luca, and Ralph A. Mosher, thedisclosure of which is totally incorporated herein by reference,discloses an improved composition comprising a photopatternable polymercontaining at least some monomer repeat units withphotosensitivity-imparting substituents, said photopatternable polymerbeing of the general formula

[0053] wherein x is an integer of 0 or 1, A is one of several specifiedgroups, such as

[0054] B is one of several specified groups, such as

[0055] or mixtures thereof, and n is an integer representing the numberof repeating monomer units. Also disclosed is a process for preparing athermal ink jet printhead with the aforementioned polymer and a thermalink jet printhead containing therein a layer of a crosslinked or chainextended polymer of the above formula.

[0056] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/95635Q1), filed concurrently herewith, entitled“Hydroxyalkylated High Performance Curable Polymers,” with the namedinventors Ram S. Narang and Timothy J. Fuller, the disclosure of whichis totally incorporated herein by reference, discloses a compositionwhich comprises (a) a polymer containing at least some monomer repeatunits with photosensitivity-imparting substituents which enablecrosslinking or chain extension of the polymer upon exposure to actinicradiation, said polymer being of the formula

[0057] wherein x is an integer of 0 or 1, A is one of several specifiedgroups, such as

[0058] B is one of several specified groups, such as

[0059] or mixtures thereof, and n is an integer representing the numberof repeating monomer units, wherein said photosensitivity-impartingsubstituents are hydroxyalkyl groups; (b) at least one member selectedfrom the group consisting of photoinitiators and sensitizers; and (c) anoptional solvent. Also disclosed are processes for preparing the abovepolymers and methods of preparing thermal ink jet printheads containingthe above polymers.

[0060] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/95635Q2), filed concurrently herewith, entitled “ImprovedHigh Performance Polymer Compositions,” with the named inventors ThomasW. Smith, Timothy J. Fuller, Ram S. Narang, and David J. Luca, thedisclosure of which is totally incorporated herein by reference,discloses a composition comprising a polymer with a weight averagemolecular weight of from about 1,000 to about 65,000, said polymercontaining at least some monomer repeat units with a first,photosensitivity-imparting substituent which enables crosslinking orchain extension of the polymer upon exposure to actinic radiation, saidpolymer also containing a second, thermal sensitivity-impartingsubstituent which enables further polymerization of the polymer uponexposure to temperatures of about 140° C. and higher, wherein the firstsubstituent is not the same as the second substituent, said polymerbeing selected from the group consisting of polysulfones,polyphenylenes, polyether sulfones, polyimides, polyamide imides,polyarylene ethers, polyphenylene sulfides, polyarylene ether ketones,phenoxy resins, polycarbonates, polyether imides, polyquinoxalines,polyquinolines, polybenzimidazoles, polybenzoxazoles,polybenzothiazoles, polyoxadiazoles, copolymers thereof, and mixturesthereof.

[0061] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/95636), filed concurrently herewith, entitled “Process forDirect Substitution of High Performance Polymers with Unsaturated EsterGroups,” with the named inventors Timothy J. Fuller, Ram S. Narang,Thomas W. Smith, David J. Luca, and Raymond K. Crandall, the disclosureof which is totally incorporated herein by reference, discloses aprocess which comprises reacting a polymer of the general formula

[0062] wherein x is an integer of 0 or 1, A is one of several specifiedgroups, such as

[0063] B is one of several specified groups, such as

[0064] or mixtures thereof, and n is an integer representing the numberof repeating monomer units, with (i) a formaldehyde source, and (ii) anunsaturated acid in the presence of an acid catalyst, thereby forming acurable polymer with unsaturated ester groups. Also disclosed is aprocess for preparing an ink jet printhead with the above polymer.

[0065] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/95637), filed concurrently herewith, entitled “Process forHaloalkylation of High Performance Polymers,” with the named inventorsTimothy J. Fuller, Ram S. Narang, Thomas W. Smith, David J. Luca, andRaymond K. Crandall, the disclosure of which is totally incorporatedherein by reference, discloses a process which comprises reacting apolymer of the general formula

[0066] wherein x is an integer of 0 or 1, A is one of several specifiedgroups, such as

[0067] B is one of several specified groups, such as

[0068] or mixtures thereof, and n is an integer representing the numberof repeating monomer units, with an acetyl halide and dimethoxymethanein the presence of a halogen-containing Lewis acid catalyst andmethanol, thereby forming a haloalkylated polymer. In a specificembodiment, the haloalkylated polymer is then reacted further to replaceat least some of the haloalkyl groups with photosensitivity-impartinggroups. Also disclosed is a process for preparing a thermal ink jetprinthead with the aforementioned polymer.

[0069] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/95638), filed concurrently herewith, entitled “Processesfor Substituting Haloalkylated Polymers With Unsaturated Ester, Ether,and Alkylcarboxymethylene Groups,” with the named inventors Timothy J.Fuller, Ram S. Narang, Thomas W. Smith, David J. Luca, and Raymond K.Crandall, the disclosure of which is totally incorporated herein byreference, discloses a process which comprises reacting a haloalkylatedaromatic polymer with a material selected from the group consisting ofunsaturated ester salts, alkoxide salts, alkylcarboxylate salts, andmixtures thereof, thereby forming a curable polymer having functionalgroups corresponding to the selected salt. Another embodiment of theinvention is directed to a process for preparing an ink jet printheadwith the curable polymer thus prepared.

[0070] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/96175), filed concurrently herewith, entitled “BlendsContaining Curable Polymers,” with the named inventors Ram S. Narang andTimothy J. Fuller, the disclosure of which is totally incorporatedherein by reference, discloses a composition which comprises a mixtureof (A) a first component comprising a polymer, at least some of themonomer repeat units of which have at least onephotosensitivity-imparting group thereon, said polymer having a firstdegree of photosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram and beingof the general formula

[0071] wherein x is an integer of 0 or 1, A is one of several specifiedgroups, such as

[0072] B is one of several specified groups, such as

[0073] or mixtures thereof, and n is an integer representing the numberof repeating monomer units, and (B) a second component which compriseseither (1) a polymer having a second degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram lower thanthe first degree of photosensitivity-imparting group substitution,wherein said second degree of photosensitivity-imparting groupsubstitution may be zero, wherein the mixture of the first component andthe second component has a third degree of photosensitivity-impartinggroup substitution measured in milliequivalents ofphotosensitivity-imparting group per gram which is lower than the firstdegree of photosensitivity-imparting group substitution and higher thanthe second degree of photosensitivity-imparting group substitution, or(2) a reactive diluent having at least one photosensitivity-impartinggroup per molecule and having a fourth degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram, whereinthe mixture of the first component and the second component has a fifthdegree of photosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram which ishigher than the first degree of photosensitivity-imparting groupsubstitution and lower than the fourth degree ofphotosensitivity-imparting group substitution; wherein the weightaverage molecular weight of the mixture is from about 10,000 to about50,000; and wherein the third or fifth degree ofphotosensitivity-imparting group substitution is from about 0.25 toabout 2 milliequivalents of photosensitivity-imparting groups per gramof mixture. Also disclosed is a process for preparing a thermal ink jetprinthead with the aforementioned composition.

[0074] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/96177), filed concurrently herewith, entitled“Halomethylated High Performance Curable Polymers,” with the namedinventors Ram S. Narang and Timothy J. Fuller, the disclosure of whichis totally incorporated herein by reference, discloses a process whichcomprises the steps of (a) providing a polymer containing at least somemonomer repeat units with halomethyl group substituents which enablecrosslinking or chain extension of the polymer upon exposure to aradiation source which is electron beam radiation, x-ray radiation, ordeep ultraviolet radiation, said polymer being of the formula

[0075] wherein x is an integer of 0 or 1, A is one of several specifiedgroups, such as

[0076] B is one of several specified groups, such as

[0077] or mixtures thereof, and n is an integer representing the numberof repeating monomer units, and (b) causing the polymer to becomecrosslinked or chain extended through the photosensitivity-impartinggroups. Also disclosed is a process for preparing a thermal ink jetprinthead by the aforementioned curing process.

[0078] Copending application U.S. Ser. No. (not yet assigned; AttorneyDocket No. D/96178), filed concurrently herewith, entitled “AqueousDevelopable High Performance Curable Polymers,” with the named inventorsRam S. Narang and Timothy J. Fuller, the disclosure of which is totallyincorporated herein by reference, discloses a composition whichcomprises a polymer containing at least some monomer repeat units withwater-solubility-imparting substituents and at least some monomer repeatunits with photosensitivity-imparting substituents which enablecrosslinking or chain extension of the polymer upon exposure to actinicradiation, said polymer being of the formula

[0079] wherein x is an integer of 0 or 1, A is one of several specifiedgroups, such as

[0080] B is one of several specified groups, such as

[0081] or mixtures thereof, and n is an integer representing the numberof repeating monomer units. In one embodiment, a single functional groupimparts both photosensitivity and water solubility to the polymer. Inanother embodiment, a first functional group imparts photosensitivity tothe polymer and a second functional group imparts water solubility tothe polymer. Also disclosed is a process for preparing a thermal ink jetprinthead with the aforementioned polymers.

[0082] While known compositions and processes are suitable for theirintended purposes, a need remains for improved materials suitable formicroelectronics applications. A need also remains for improved ink jetprintheads. Further, there is a need for photopatternable polymericmaterials which are heat stable, electrically insulating, andmechanically robust. Additionally, there is a need for photopatternablepolymeric materials which are chemically inert with respect to thematerials that might be employed in ink jet ink compositions. There isalso a need for photopatternable polymeric materials which exhibit lowshrinkage during post-cure steps in microelectronic device fabricationprocesses. In addition, a need remains for photopatternable polymericmaterials which exhibit a relatively long shelf life. Further, there isa need for photopatternable polymeric materials which can be patternedwith relatively low photo-exposure energies. Additionally, a needremains for photopatternable polymeric materials which, in the curedform, exhibit good solvent resistance. There is also a need forphotopatternable polymeric materials which, when applied tomicroelectronic devices by spin casting techniques and cured, exhibitreduced edge bead and no apparent lips and dips. In addition, a needremains for photopatternable polymeric materials which allow theproduction of high aspect ratio features at very high resolutions.Further, a need remains for photopatternable polymeric materials whichfunction as a barrier layer and which may also be able to function as anadhesive layer in thermal ink jet printheads, possibly eliminating theneed for an additional adhesive layer to bond the heater plate to thechannel plate. Additionally, there is a need for photopatternablepolymeric materials which exhibit improved adhesion to the heater plateof a thermal ink jet printhead. In addition, there remains a need forphotopatternable polymeric materials which have relatively lowdielectric constants. Further, there is a need for photopatternablepolymeric materials which exhibit reduced water sorption. Additionally,a need remains for photopatternable polymeric materials which exhibitimproved hydrolytic stability, especially upon exposure to alkalinesolutions. A need also remains for photopatternable polymeric materialswhich are stable at high temperatures, typically greater than about 150°C. There is also a need for photopatternable polymeric materials whicheither have high glass transition temperatures or are sufficientlycrosslinked that there are no low temperature phase transitionssubsequent to photoexposure. Further, a need remains forphotopatternable polymeric materials with low coefficients of thermalexpansion. There is a need for polymers which are thermally stable,patternable as thick films of about 30 microns or more, exhibit lowT_(g) prior to photoexposure, have low dielectric constants, are low inwater absorption, have low coefficients of expansion, have desirablemechanical and adhesive characteristics, and are generally desirable forinterlayer dielectric applications, including those at hightemperatures, which are also photopatternable. There is also a need forphotoresist compositions with good to excellent processingcharacteristics.

SUMMARY OF THE INVENTION

[0083] It is an object of the present invention to provide polymericmaterials with the above noted advantages.

[0084] It is another object of the present invention to provide improvedmaterials suitable for microelectronics applications.

[0085] It is yet another object of the present invention to provideimproved ink jet printheads.

[0086] It is still another object of the present invention to providephotopatternable polymeric materials which are heat stable, electricallyinsulating, and mechanically robust.

[0087] Another object of the present invention is to providephotopatternable polymeric materials which are chemically inert withrespect to the materials that might be employed in ink jet inkcompositions.

[0088] Yet another object of the present invention is to providephotopatternable polymeric materials which exhibit low shrinkage duringpost-cure steps in microelectronic device fabrication processes.

[0089] Still another object of the present invention is to providephotopatternable polymeric materials which exhibit a relatively longshelf life.

[0090] It is another object of the present invention to providephotopatternable polymeric materials which can be patterned withrelatively low photo-exposure energies.

[0091] It is yet another object of the present invention to providephotopatternable polymeric materials which, in the cured form, exhibitgood solvent resistance.

[0092] It is still another object of the present invention to providephotopatternable polymeric materials which, when applied tomicroelectronic devices by spin casting techniques and cured, exhibitreduced edge bead and no apparent lips and dips.

[0093] Another object of the present invention is to providephotopatternable polymeric materials which allow the production of highaspect ratio features at very high resolutions.

[0094] Yet another object of the present invention is to providephotopatternable polymeric materials which function as a barrier layerand which may also be able to function as an adhesive layer in thermalink jet printheads, possibly eliminating the need for an additionaladhesive layer to bond the heater plate to the channel plate.

[0095] Still another object of the present invention is to providephotopatternable polymeric materials which exhibit improved adhesion tothe heater plate of a thermal ink jet printhead.

[0096] It is another object of the present invention to providephotopatternable polymeric materials which have relatively lowdielectric constants.

[0097] It is yet another object of the present invention to providephotopatternable polymeric materials which exhibit reduced watersorption.

[0098] It is still another object of the present invention to providephotopatternable polymeric materials which exhibit improved hydrolyticstability, especially upon exposure to alkaline solutions.

[0099] Another object of the present invention is to providephotopatternable polymeric materials which are stable at hightemperatures, typically greater than about 150° C.

[0100] Yet another object of the present invention is to providephotopatternable polymeric materials which either have high glasstransition temperatures or are sufficiently crosslinked that there areno low temperature phase transitions subsequent to photoexposure.

[0101] Still another object of the present invention is to providephotopatternable polymeric materials with low coefficients of thermalexpansion.

[0102] It is another object of the present invention to provide polymerswhich are thermally stable, patternable as thick films of about 30microns or more, exhibit low T_(g) prior to photoexposure, have lowdielectric constants, are low in water absorption, have low coefficientsof expansion, have desirable mechanical and adhesive characteristics,and are generally desirable for interlayer dielectric applications,which are also photopatternable.

[0103] It is yet another object of the present invention to providephotoresist compositions with good to excellent processingcharacteristics.

[0104] These and other objects of the present invention (or specificembodiments thereof) can be achieved by providing a composition whichcomprises a polymer containing at least some monomer repeat units withphotosensitivity-imparting substituents which enable crosslinking orchain extension of the polymer upon exposure to actinic radiation, saidpolymer being of the formula

[0105] wherein x is an integer of 0 or 1, A is

[0106] or mixtures thereof, B is

[0107] wherein v is an integer of from 1 to about 20,

[0108] wherein z is an integer of from 2 to about 20,

[0109] wherein u is an integer of from 1 to about 20,

[0110] wherein w is an integer of from 1 to about 20,

[0111] or mixtures thereof, and n is an integer representing the numberof repeating monomer units, wherein said photosensitivity-impartingsubstituents are allyl ether groups, epoxy groups, or mixtures thereof.Another embodiment of the present invention is directed to a processwhich comprises the steps of:

[0112] (a) depositing a layer comprising a polymer of the above formulaonto a lower substrate in which one surface thereof has an array ofheating elements and addressing electrodes having terminal ends formedthereon, said polymer being deposited onto the surface having theheating elements and addressing electrodes thereon;

[0113] (b) exposing the layer to actinic radiation in an imagewisepattern such that the polymer in exposed areas becomes crosslinked orchain extended and the polymer in unexposed areas does not becomecrosslinked or chain extended, wherein the unexposed areas correspond toareas of the lower substrate having thereon the heating elements and theterminal ends of the addressing electrodes;

[0114] (c) removing the polymer from the unexposed areas, therebyforming recesses in the layer, said recesses exposing the heatingelements and the terminal ends of the addressing electrodes;

[0115] (d) providing an upper substrate with a set of parallel groovesfor subsequent use as ink channels and a recess for subsequent use as amanifold, the grooves being open at one end for serving as dropletemitting nozzles; and

[0116] (e) aligning, mating, and bonding the upper and lower substratestogether to form a printhead with the grooves in the upper substratebeing aligned with the heating elements in the lower substrate to formdroplet emitting nozzles, thereby forming a thermal ink jet printhead.Yet other embodiments of the present invention are directed to processesfor preparing the aforementioned polymers.

BRIEF DESCRIPTION OF THE DRAWINGS

[0117]FIG. 1 is an enlarged schematic isometric view of an example of aprinthead mounted on a daughter board showing the droplet emittingnozzles.

[0118]FIG. 2 is an enlarged cross-sectional view of FIG. 1 as viewedalong the line 2-2 thereof and showing the electrode passivation and inkflow path between the manifold and the ink channels.

[0119]FIG. 3 is an enlarged cross-sectional view of an alternateembodiment of the printhead in FIG. 1 as viewed along the line 2-2thereof.

DETAILED DESCRIPTION OF THE INVENTION

[0120] The present invention is directed to curable polymers. Thecurable polymers of the present invention are prepared from polymers ofthe following formula:

[0121] wherein x is an integer of 0 or 1, A is

[0122] or mixtures thereof, B is

[0123] wherein v is an integer of from 1 to about 20, and preferablyfrom 1 to about 10,

[0124] wherein z is an integer of from 2 to about 20, and preferablyfrom 2 to about 10,

[0125] wherein u is an integer of from 1 to about 20, and preferablyfrom 1 to about 10,

[0126] wherein w is an integer of from 1 to about 20, and preferablyfrom 1 to about 10,

[0127] other similar bisphenol derivatives, or mixtures thereof, and nis an integer representing the number of repeating monomer units. Thevalue of n is such that the weight average molecular weight of thematerial typically is from about 1,000 to about 100,000, preferably fromabout 1,000 to about 65,000, more preferably from about 1,000 to about40,000, and even more preferably from about 3,000 to about 25,000,although the weight average molecular weight can be outside theseranges. Preferably, n is an integer of from about 2 to about 70, morepreferably from about 5 to about 70, and even more preferably from about8 to about 50, although the value of n can be outside these ranges. Thephenyl groups and the A and/or B groups may also be substituted,although the presence of two or more substituents on the B group orthoto the oxygen groups can render substitution difficult. Substituents canbe present on the polymer either prior to or subsequent to the placementof photosensitivity-imparting functional groups thereon. Substituentscan also be placed on the polymer during the process of placement ofphotosensitivity-imparting functional groups thereon. Examples ofsuitable substituents include (but are not limited to) alkyl groups,including saturated, unsaturated, and cyclic alkyl groups, preferablywith from 1 to about 6 carbon atoms, substituted alkyl groups, includingsaturated, unsaturated, and cyclic substituted alkyl groups, preferablywith from 1 to about 6 carbon atoms, aryl groups, preferably with from 6to about 24 carbon atoms, substituted aryl groups, preferably with from6 to about 24 carbon atoms, arylalkyl groups, preferably with from 7 toabout 30 carbon atoms, substituted arylalkyl groups, preferably withfrom 7 to about 30 carbon atoms, alkoxy groups, preferably with from 1to about 6 carbon atoms, substituted alkoxy groups, preferably with from1 to about 6 carbon atoms, aryloxy groups, preferably with from 6 toabout 24 carbon atoms, substituted aryloxy groups, preferably with from6 to about 24 carbon atoms, arylalkyloxy groups, preferably with from 7to about 30 carbon atoms, substituted arylalkyloxy groups, preferablywith from 7 to about 30 carbon atoms, hydroxy groups, amine groups,imine groups, ammonium groups, pyridine groups, pyridinium groups, ethergroups, ester groups, amide groups, carbonyl groups, thiocarbonylgroups, sulfate groups, sulfonate groups, sulfide groups, sulfoxidegroups, phosphine groups, phosphonium groups, phosphate groups, mercaptogroups, nitroso groups, sulfone groups, acyl groups, acid anhydridegroups, azide groups, and the like, wherein the substituents on thesubstituted alkyl groups, substituted aryl groups, substituted arylalkylgroups, substituted alkoxy groups, substituted aryloxy groups, andsubstituted arylalkyloxy groups can be (but are not limited to) hydroxygroups, amine groups, imine groups, ammonium groups, pyridine groups,pyridinium groups, ether groups, aldehyde groups, ketone groups, estergroups, amide groups, carboxylic acid groups, carbonyl groups,thiocarbonyl groups, sulfate groups, sulfonate groups, sulfide groups,sulfoxide groups, phosphine groups, phosphonium groups, phosphategroups, cyano groups, nitrile groups, mercapto groups, nitroso groups,halogen atoms, nitro groups, sulfone groups, acyl groups, acid anhydridegroups, azide groups, mixtures thereof, and the like, wherein two ormore substituents can be joined together to form a ring. Processes forthe preparation of these materials are known, and disclosed in, forexample, P. M. Hergenrother, J. Macromol. Sci. Rev. Macromol. Chem., C19(1), 1-34 (1980); P. M. Hergenrother, B. J. Jensen, and S. J. Havens,Polymer, 29, 358 (1988); B. J. Jensen and P. M. Hergenrother, “HighPerformance Polymers,” Vol. 1, No. 1) page 31 (1989), “Effect ofMolecular Weight on Poly(arylene ether ketone) Properties”; V. Percecand B. C. Auman, Makromol. Chem. 185, 2319 (1984); “High MolecularWeight Polymers by Nickel Coupling of Aryl Polychlorides,” I. Colon, G.T. Kwaiatkowski, J. of Polymer Science, Part A, Polymer Chemistry, 28,367 (1990); M. Ueda and T. Ito, Polymer J., 23 (4), 297 (1991);“Ethynyl-Terminated Polyarylates: Synthesis and Characterization,” S. J.Havens and P. M. Hergenrother, J. of Polymer Science: Polymer ChemistryEdition, 22 3011 (1984); “Ethynyl-Terminated Polysulfones: Synthesis andCharacterization,” P. M. Hergenrother, J. of Polymer Science: PolymerChemistry Edition, 20, 3131 (1982); K. E. Dukes, M. D. Forbes, A. S.Jeevarajan, A. M. Belu, J. M. DeDimone, R. W. Linton, and V. V. Sheares,Macromolecules, 29, 3081 (1996); G. Hougham, G. Tesoro, and J. Shaw,Polym. Mater. Sci. Eng., 61, 369 (1989); V. Percec and B. C. Auman,Makromol. Chem, 185, 617 (1984); “Synthesis and characterization of NewFluorescent Poly(arylene ethers),” S. Matsuo, N. Yakoh, S. Chino, M.Mitani, and S. Tagami, Journal of Polymer Science: Part A: PolymerChemistry, 32, 1071 (1994); “Synthesis of a Novel Naphthalene-BasedPoly(arylene ether ketone) with High Solubility and Thermal Stability,”Mami Ohno, Toshikazu Takata, and Takeshi Endo, Macromolecules, 27, 3447(1994); “Synthesis and Characterization of New Aromatic Poly(etherketones),” F. W. Mercer, M. T. Mckenzie, G. Merlino, and M. M. Fone, J.of Applied Polymer Science, 56, 1397 (1995); H. C. Zhang, T. L. Chen, Y.G. Yuan, Chinese Patent CN 85108751 (1991); “Static and laser lightscattering study of novel thermoplastics. 1. Phenolphthalein poly(arylether ketone),” C. Wu, S. Bo, M. Siddiq, G. Yang and T. Chen,Macromolecules, 29, 2989 (1996); “Synthesis of t-Butyl-SubstitutedPoly(ether ketone) by Nickel-Catalyzed Coupling Polymerization ofAromatic Dichloride”, M. Ueda, Y. Seino, Y. Haneda, M. Yoneda, and J.-I.Sugiyama, Journal of Polymer Science: Part A: Polymer Chemistry, 32, 675(1994); “Reaction Mechanisms: Comb-Like Polymers and Graft Copolymersfrom Macromers 2. Synthesis, Characterzation and Homopolymerization of aStyrene Macromer of Poly(2,6-dimethyl-1,4-phenylene Oxide),” V. Percec,P. L. Rinaidi, and B. C. Auman, Polymer Bulletin, 10, 397 (1983);Handbook of Polymer Synthesis Part A, Hans R. Kricheldorf, ed., MarcelDekker, Inc., New York-Basel-Hong Kong (1992); and “Introduction ofCarboxyl Groups into Crosslinked Polystyrene,” C. R. Harrison, P. Hodge,J. Kemp, and G. M. Perry, Die Makromolekulare Chemie, 176, 267 (1975),the disclosures of each of which are totally incorporated herein byreference. Further background on high performance polymers is disclosedin, for example, U.S. Pat. Nos. 2,822,351; 3,065,205; British Pat. No.1,060,546; British Pat. No. 971,227; British Pat. No. 1,078,234; U.S.Pat. No. 4,175,175; N. Yoda and H. Hiramoto, J. Macromol. Sci.-Chem.,A21 (13 &14) pp. 1641 (1984) (Toray Industries, Inc., Otsu, Japan; B.Sillion and L. Verdet, “Polyimides and other High-Temperature polymers”,edited by M. J. M. Abadie and B. Sillion, Elsevier Science PublishersB.V. (Amsterdam 1991); “Polyimides with Alicyclic Diamines. II. HydrogenAbstraction and Photocrosslinking Reactions of Benzophenone TypePolyimides,” Q. Jin, T. Yamashita, and K. Horie, J. of Polymer Science:Part A: Polymer Chemistry, 32, 503 (1994); Probimide™ 300, productbulletin, Ciba-Geigy Microelectronics Chemicals, “PhotosensitivePolyimide System”; High Performance Polymers and Composites, J. I.Kroschwitz (ed.), John Wiley & Sons (New York 1991); and T. E. Atwood,D. A. Barr, T. A. King, B. Newton, and B. J. Rose, Polymer, 29, 358(1988), the disclosures of each of which are totally incorporated hereinby reference. Further information on radiation curing is disclosed in,for example, Radiation Curing: Science and Technology, S. Peter Pappas,ed., Plenum Press (New York 1992), the disclosure of which is totallyincorporated herein by reference.

[0128] For applications wherein the photopatternable polymer is to beused as a layer in a thermal ink jet printhead, the polymer preferablyhas a number average molecular weight of from about 3,000 to about20,000 Daltons, more preferably from about 3,000 to about 10,000Daltons, and even more preferably from about 3,500 to about 6,500Daltons, although the molecular weight can be outside this range.

[0129] The polymer to be functionalized with epoxy or allyl ether groupscan be functionalized by any desired or suitable process. One methodentails preparation of a haloalkylated intermediate, followed bysubstitution with unsaturated ether or allyl ether groups and, ifdesired, subsequent epoxidation of the unsaturated ether or allyl ethergroups. Haloalkylation of the polymer can be carried out by any suitableor desired process. For example, suitable haloalkylation processesinclude reaction of the polymers with formaldehyde and hydrohalic acid,bishalomethyl ether, halomethyl methyl ether, octylhalomethyl ether, orthe like, generally in the presence of a Lewis acid catalyst.Bromination of a methyl group on the polymer can also be accomplishedwith elemental bromine via a free radical process initiated by, forexample, a peroxide initiator or light. Halogen atoms can be substitutedfor other halogens already on a halomethyl group by, for example,reaction with the appropriate hydrohalic acid or halide salt. Methodsfor the haloalkylation of polymers are also disclosed in, for example,“Chloromethylation of Condensation Polymers Containing anoxy-1,4-phenylene Backbone,” W. H. Daly et al., Polymer Preprints, Vol.20, No. 1, 835 (1979), the disclosure of which is totally incorporatedherein by reference.

[0130] The haloalkylation of the polymer can be accomplished by reactingthe polymer with an acetyl halide and dimethoxymethane in the presenceof a halogen-containing Lewis acid catalyst such as those of the generalformula

M^(n⊕)X_(n)

[0131] wherein n is an integer of 1, 2, 3, 4, or 5, M represents a boronatom or a metal atom, such as tin, aluminum, zinc, antimony, iron (III),gallium, indium, arsenic, mercury, copper, platinum, palladium, or thelike, and X represents a halogen atom, such as fluorine, chlorine,bromine, or iodine, with specific examples including SnCl₄, AlCl₃,ZnCl₂, AlBr₃, BF₃, SbF₅, Fel₃, GaBr₃, InCl₃, Asl₅, HgBr₂, CuCl, PdCl₂,PtBr₂, or the like. Methanol is added to generate hydrohalic acidcatalytically; the hydrohalic acid reacts with dimethoxymethane to formhalomethyl methyl ether. Care must be taken to avoid cross-linking ofthe halomethylated polymer. Typically, the reactants are present inrelative amounts by weight of about 35.3 parts acetyl halide, about 37parts dimethoxymethane, about 1.2 parts methanol, about 0.3 parts Lewisacid catalyst, about 446 parts 1,1,2,2-tetrachloroethane, and about 10to 20 parts polymer. 1,1,2,2-Tetrachlorethane is a suitable reactionsolvent. Dichloromethane is low boiling, and consequently the reactionis slow in this solvent unless suitable pressure equipment is used.

[0132] The general reaction scheme is as follows:

[0133] wherein R′ and R″ each, independently of the other, can be (butare not limited to) hydrogen atoms, alkyl groups, including saturated,unsaturated, and cyclic alkyl groups, preferably with from 1 to about 11carbon atoms, substituted alkyl groups, preferably with from 1 to about11 carbon atoms, aryl groups, preferably with from 6 to about 11 carbonatoms, substituted aryl groups, preferably with from 6 to about 11carbon atoms, arylalkyl groups, preferably with from 7 to about 11carbon atoms, substituted arylalkyl groups, preferably with from 7 toabout 11 carbon atoms, and the like. The resulting material is of thegeneral formula

[0134] wherein n is an integer of 1, 2, 3, 4, or 5, R is an alkyl group,including both saturated, unsaturated, linear, branched, and cyclicalkyl groups, preferably with from 1 to about 11 carbon atoms, morepreferably with from 1 to about 5 carbon atoms, even more preferablywith from 1 to about 3 carbon atoms, and most preferably with 1 carbonatom, or a substituted alkyl group, an arylalkyl group, preferably withfrom 7 to about 29 carbon atoms, more preferably with from 7 to about 17carbon atoms, even more preferably with from 7 to about 13 carbon atoms,and most preferably with from 7 to about 9 carbon atoms, or asubstituted arylalkyl group, and X is a halogen atom, such as fluorine,chlorine, bromine, or iodine, a, b, c, and d are each integers of 0, 1,2, 3, or 4, provided that at least one of a, b, c, and d is equal to orgreater than 1 in at least some of the monomer repeat units of thepolymer, and n is an integer representing the number of repeatingmonomer units. Examples of suitable substituents on the substitutedalkyl, aryl, and arylalkyl groups include (but are not limited to) alkylgroups, including saturated, unsaturated, linear, branched, and cyclicalkyl groups, preferably with from 1 to about 6 carbon atoms,substituted alkyl groups, preferably with from 1 to about 6 carbonatoms, aryl groups, preferably with from 6 to about 24 carbon atoms,substituted aryl groups, preferably with from 6 to about 24 carbonatoms, arylalkyl groups, preferably with from 7 to about 30 carbonatoms, substituted arylalkyl groups, preferably with from 7 to about 30carbon atoms, alkoxy groups, preferably with from 1 to about 6 carbonatoms, substituted alkoxy groups, preferably with from 1 to about 6carbon atoms, aryloxy groups, preferably with from 6 to about 24 carbonatoms, substituted aryloxy groups, preferably with from 6 to about 24carbon atoms, arylalkyloxy groups, preferably with from 7 to about 30carbon atoms, substituted arylalkyloxy groups, preferably with from 7 toabout 30 carbon atoms, amine groups, imine groups, ammonium groups,pyridine groups, pyridinium groups, ether groups, ester groups, amidegroups, carbonyl groups, thiocarbonyl groups, sulfate groups, sulfonategroups, sulfide groups, sulfoxide groups, phosphine groups, phosphoniumgroups, phosphate groups, mercapto groups, nitroso groups, sulfonegroups, acyl groups, acid anhydride groups, azide groups, and the like,wherein the substituents on the substituted alkyl groups, substitutedaryl groups, substituted arylalkyl groups, substituted alkoxy groups,substituted aryloxy groups, and substituted arylalkyloxy groups can be(but are not limited to) hydroxy groups, amine groups, imine groups,ammonium groups, pyridine groups, pyridinium groups, ether groups,aldehyde groups, ketone groups, ester groups, amide groups, carboxylicacid groups, carbonyl groups, thiocarbonyl groups, sulfate groups,sulfonate groups, sulfide groups, sulfoxide groups, phosphine groups,phosphonium groups, phosphate groups, cyano groups, nitrile groups,mercapto groups, nitroso groups, halogen atoms, nitro groups, sulfonegroups, acyl groups, acid anhydride groups, azide groups, mixturesthereof, and the like, wherein two or more substituents can be joinedtogether to form a ring. Substitution is generally random, although thesubstituent often indicates a preference for the B group, and any givenmonomer repeat unit may have no haloalkyl substituents, one haloalkylsubstituent, or two or more haloalkyl substituents.

[0135] Typical reaction temperatures are from about 60 to about 120° C.,and preferably from about 80 to about 110° C., although the temperaturecan be outside these ranges. Typical reaction times are from about 1 toabout 10 hours, and preferably from about 2 to about 4 hours, althoughthe time can be outside these ranges. Longer reaction times generallyresult in higher degrees of haloalkylation. When the haloalkylatedpolymer is used as an intermediate material in the synthesis of polymerssubstituted with allyl ether or epoxy groups, higher degrees ofhaloalkylation generally enable higher degrees of substitution with thedesired group and thereby enable greater photosensitivity of thepolymer. Different degrees of haloalkylation may be desirable fordifferent applications. When the material is used as an intermediate inthe synthesis of the epoxidized polymer, too high a degree ofsubstitution may lead to the loss of bonding because a high crosslinkdensity embrittles the polymer, leading to possible cohesive failure,whereas too low a degree of substitution may be undesirable becauseinadequate crosslinking may result and insufficient groups are availableto bond to the substrate, leading to adhesive failure. For applicationswherein the photopatternable allyl ether substituted or epoxidizedpolymer is to be used as a layer in a thermal ink jet printhead, thedegree of substitution (i.e., the average number of allyl ether or epoxygroups per monomer repeat unit) preferably is from about 0.5 about 1.5,and more preferably is about 1.0, although the degree of substitutioncan be outside these ranges for ink jet printhead applications. Thisamount of substitution amounts to from about 0.8 to about 1.3milliequivalents of allyl ether or epoxy groups per gram of resin. Forthermosetting resin (composited) applications, such as epoxy circuitboards and the like, a degree of substitution of from about 0.5 to about2.0 epoxy groups per monomer repeat unit may be preferred.

[0136] The haloalkylated polymer is allyl ether substituted orepoxidized by first reacting the haloalkylated polymer with anunsaturated alcohol salt, such as an allyl alcohol salt, in solution.Examples of suitable unsaturated alcohol salts and allyl alcohol saltsinclude sodium 2-allylphenolate, sodium 4-allylphenolate, sodium allylalcoholate, corresponding salts with lithium, potassium, cesium,rubidium, ammonium, quaternary alkyl ammonium compounds, and the like.Unsaturated alcohol salts can be generated by the reaction of thealcohol with a base, such as sodium hydride, sodium hydroxide, or thelike. The salt displaces the halide of the haloalkyl groups at betweenabout 25 and about 100° C. Examples of solvents suitable for thereaction include polar aprotic solvents such as N,N-dimethylacetamide,dimethylsulfoxide, N-methylpyrrolidinone, dimethylformamide,tetrahydrofuran, and the like. Typically, the reactants are present inrelative amounts with respect to each other of from about 1 to about 50molar equivalents of unsaturated alcohol salt per haloalkyl group to besubstituted, although the relative amounts can be outside this range.Typically, the reactants are present in solution in amounts of fromabout 5 to about 50 percent by weight solids, and preferably about 10percent by weight solids, although the relative amounts can be outsidethis range.

[0137] Typical reaction temperatures are from about 25 to about 100° C.,and preferably from about 25 to about 50° C., although the temperaturecan be outside these ranges. Typical reaction times are from about 4 toabout 24 hours, and preferably about 16 hours, although the time can beoutside this range.

[0138] The general reaction scheme, illustrated below with achloromethylated polymer and an allyl alcoholate salt, is as follows:

[0139] wherein X is any suitable cation, such as sodium, potassium, orthe like, a, b, c, d, e, f, g, h, i, j, k, and m are each integers of 0,1, 2, 3, or 4, provided that the sum of i+e is no greater than 4, thesum of j+f is no greater than 4, the sum of k+g is no greater than 4,and the sum of m+h is no greater than 4, provided that at least one ofa, b, c, and d is equal to or greater than 1 in at least some of themonomer repeat units of the polymer, and provided that at least one ofe, f, g, and h is equal to at least 1 in at least some of the monomerrepeat units of the polymer, and n is an integer representing the numberof repeating monomer units, and n is an integer representing the numberof repeating monomer units. In the corresponding reaction with the2-allylphenolate salt, the reaction proceeds as shown above except thatthe

[0140] groups shown above are replaced with

[0141] groups.

[0142] The allyl ether substituted polymer is suitable for photoinducedcuring reactions. Alternatively, the allyl ether substituted polymer (orthe unsaturated ether substituted polymer) can be used as anintermediate in the synthesis of the epoxidized polymer. This allylether or unsaturated ether substituted intermediate product isthereafter reacted with a peroxide, such as hydrogen peroxide,m-chloroperoxybenzoic acid, acetyl peroxide, and the like, as well asmixtures thereof, to yield the epoxidized polymer. Typically, thereactants are present in relative amounts with respect to each other offrom approximately equivalent molar amounts of peroxide and the numberof unsaturated groups desired to be converted to epoxide groups to anexcess of between 10 and 100 mole percent of peroxide. The reactionpreferably takes place in a dilute solution of about 1 percent by weightsolids or less to prevent crosslinking.

[0143] The general reaction scheme, illustrated below with the allylalcoholate substituents, is as follows:

[0144] wherein a, b, c, d, e, f, g, h, p, q, r, and s are each integersof 0, 1, 2, 3, or 4, provided that the sum of a+e+p is no greater than4, the sum of b+f+q is no greater than 4, the sum of c+g+r is no greaterthan 4, and the sum of d+h+s is no greater than 4, provided that atleast one of p, q, r, and s is equal to or greater than 1 in at leastsome of the monomer repeat units of the polymer, and n is an integerrepresenting the number of repeating monomer units.

[0145] Some or all of the haloalkyl groups can be replaced with allylether or epoxy substituents. Longer reaction times generally lead togreater degrees of substitution of haloalkyl groups with allyl ether orepoxy substituents. In one preferred embodiment, some of the haloalkylgroups remain on the polymer (i.e., at least one of a, b, c, or d isequal to at least 1 in at least some of the monomer repeat units of thepolymer). In this embodiment, the polymer can, if desired, be furtherreacted to convert the haloalkyl groups to, for example, unsaturatedester groups.

[0146] Typical reaction temperatures for the conversion of theunsaturated ether groups to the epoxy groups are from about 0 to about50° C., and preferably from about 0 to about 25° C., although thetemperature can be outside these ranges. Typical reaction times are fromabout 1 to about 24 hours, and preferably from about 4 to about 16hours, although the time can be outside these ranges. Typical solventsfor this reaction include methylene chloride, chloroform, carbontetrachloride, and the like.

[0147] The epoxidized polymer can also be prepared by reaction of thehaloalkylated polymer with an epoxy-group-containing alcohol salt, suchas a glycidolate salt, or an unsaturated alcohol salt, such as those setforth hereinabove, in the presence of a molar excess of base (withrespect to the unsaturated alcohol salt or epoxy-group-containingalcohol salt), such as sodium hydride, sodium hydroxide, potassiumcarbonate, quaternary alkyl ammonium salts, or the like, under phasetransfer conditions. Examples of suitable glycidolate salts includesodium glycidolate and the like. Typically, the reactants are present inrelative amounts with respect to each other of from approximatelyequivalent molar amounts of alcohol and the number of unsaturated groupsdesired to be converted to epoxide groups. Typically, the reactants arepresent in solution in amounts of from about 1 to about 10 percent byweight solids, although other concentrations can be employed. Thereaction with bases such as sodium hydroxide and potassium carbonatetypically takes place at from about 25 to about 100° C. The reactionwith sodium hydride with glycidol or the unsaturated alcohol generallyoccurs at ice bath temperatures. Typical reaction times are about 16hours, although other times may be employed. Examples of suitablesolvents include dimethyl acetamide, tetrahydrofuran, mixtures thereof,and the like.

[0148] The general reaction scheme is as follows:

[0149] Unsaturated ether or allyl ether groups can also be placed on thehaloalkylated polymer by other methods, such as by a Grignard reaction,a Wittig reaction, or the like.

[0150] Other procedures for placing functional groups on aromaticpolymers are disclosed in, for example, W. H. Daly, S. Chotiwana, and R.Nielsen, Polymer Preprints, 20(1), 835 (1979); “Functional Polymers andSequential Copolymers by Phase Transfer Catalysis, 3. Synthesis AndCharacterization of Aromatic Poly(ether sulfone)s andPoly(oxy-2,6-dimethyl-1,4-phenylene) Containing Pendant Vinyl Groups,”V. Percec and B. C. Auman, Makromol. Chem., 185, 2319 (1984); F. Wangand J. Roovers, Journal of Polymer Science: Part A: Polymer Chemistry,32, 2413 (1994); “Details Concerning the Chloromethylation of SolubleHigh Molecular Weight Polystyrene Using Dimethoxymethane, ThionylChloride, And a Lewis Acid: A Full Analysis,” M. E. Wright, E. G.Toplikar, and S. A. Svejda, Macromolecules, 24, 5879 (1991); “FunctionalPolymers and Sequential Copolymers by Phase Transfer Catalysts,” V.Percec and P. L. Rinaldi, Polymer Bulletin, 10, 223 (1983); “Preparationof Polymer Resin and Inorganic Oxide Supported Peroxy-Acids and TheirUse in the Oxidation of Tetrahydrothiophene,” J. A. Greig, R. D.Hancock, and D. C. Sherrington, Euopeon Polymer J., 16, 293 (1980);“Preparation of Poly(vinylbenzyltriphenylphosphonium Perbromide) and ItsApplication in the Bromination of Organic Compounds,” A. Akelah, M.Hassanein, and F. Abdel-Galil, European Polymer J., 20 (3) 221 (1984);J. M. J. Frechet and K. K. Haque, Macromelcules, 8, 130 (1975); U.S.Pat. Nos. 3,914,194; 4,110,279; 3,367,914; “Synthesis of Intermediatesfor Production of Heat Resistant Polymers (Chloromethylation of Diphenyloxide),” E. P. Tepenitsyna, M. I. Farberov, and A. P. Ivanovski, ZhurnalPrikladnoi Khimii, Vol. 40, No. 11, 2540 (1967); U.S. Pat. No.3,000,839; Chem Abst. 56, 590f (1962); U.S. Pat. No. 3,128,258; ChemAbstr. 61, 4560a (1964); J. D. Doedens and H. P. Cordts, Ind. Eng. Ch.,83, 59 (1961); British Pat. No. 863,702; and Chem Abstr 55, 18667b(1961); the disclosures of each of which are totally incorporated hereinby reference.

[0151] While not required, it may be advantageous with respect to theultimate properties of the photopatterned polymer if the polymer isfunctionalized with a second thermally polymerizable group, typically(although not necessarily) one which reacts at a temperature in excessof the glass transition temperature of the crosslinked or chain extendedphotopatternable polymer. The second polymerizable group can be eitherappended to the polymer chain or present as a terminal end group.

[0152] Examples of suitable thermal sensitivity imparting groups includeethynyl groups, such as those of the formula

—(R)_(a)—C≡C—R′

[0153] wherein R is

[0154] a is an integer of 0 or 1, and R′ is a hydrogen atom or a phenylgroup, ethylenic linkage-containing groups, such as allyl groups,including those of the formula

[0155] wherein X and Y each, independently of the other, are hydrogenatoms or halogen atoms, such as fluorine, chlorine, bromine, or iodine,vinyl groups, including those of the formula

[0156] wherein R is an alkyl group, including both saturated,unsaturated, linear, branched, and cyclic alkyl groups, preferably withfrom 1 to about 30 carbon atoms, more preferably with from 1 to about 11carbon atoms, even more preferably with from 1 to about 5 carbon atoms,a substituted alkyl group, an aryl group, preferably with from 6 toabout 24 carbon atoms, more preferably with from 6 to about 18 carbonatoms, a substituted aryl group, an arylalkyl group, preferably withfrom 7 to about 30 carbon atoms, more preferably with from 7 to about 19carbon atoms, or a substituted arylalkyl group, wherein the substituentson the substituted alkyl groups, substituted aryl groups, substitutedarylalkyl groups, substituted alkoxy groups, substituted aryloxy groups,and substituted arylalkyloxy groups can be (but are not limited to)hydroxy groups, amine groups, imine groups, ammonium groups, pyridinegroups, pyridinium groups, ether groups, aldehyde groups, ketone groups,ester groups, amide groups, carboxylic acid groups, carbonyl groups,thiocarbonyl groups, sulfate groups, sulfonate groups, sulfide groups,sulfoxide groups, phosphine groups, phosphonium groups, phosphategroups, cyano groups, nitrile groups, mercapto groups, nitroso groups,halogen atoms, nitro groups, sulfone groups, acyl groups, acid anhydridegroups, azide groups, mixtures thereof, and the like, wherein any two ormore substituents can be joined together to form a ring, vinyl ethergroups, such as those of the formula

[0157] epoxy groups, including those of the formula

[0158] R is an alkyl group, including both saturated, unsaturated,linear, branched, and cyclic alkyl groups, preferably with from 1 toabout 30 carbon atoms, more preferably with from 1 to about 11 carbonatoms, even more preferably with from 1 to about 5 carbon atoms, asubstituted alkyl group, an aryl group, preferably with from 6 to about24 carbon atoms, more preferably with from 6 to about 18 carbon atoms, asubstituted aryl group, an arylalkyl group, preferably with from 7 toabout 30 carbon atoms, more preferably with from 7 to about 19 carbonatoms, or a substituted arylalkyl group, wherein the substituents on thesubstituted alkyl groups, substituted aryl groups, substituted arylalkylgroups, substituted alkoxy groups, substituted aryloxy groups, andsubstituted arylalkyloxy groups can be (but are not limited to) hydroxygroups, amine groups, imine groups, ammonium groups, pyridine groups,pyridinium groups, ether groups, aldehyde groups, ketone groups, estergroups, amide groups, carboxylic acid groups, carbonyl groups,thiocarbonyl groups, sulfate groups, sulfonate groups, sulfide groups,sulfoxide groups, phosphine groups, phosphonium groups, phosphategroups, cyano groups, nitrile groups, mercapto groups, nitroso groups,halogen atoms, nitro groups, sulfone groups, acyl groups, acid anhydridegroups, azide groups, mixtures thereof, and the like, wherein any two ormore substituents can be joined together to form a ring, halomethylgroups, such as fluoromethyl groups, chloromethyl groups, bromomethylgroups, and iodomethyl groups, hydroxymethyl groups, benzocyclobutenegroups, including those of the formula

[0159] phenolic groups (-φ-OH), provided that the phenolic groups arepresent in combination with either halomethyl groups or hydroxymethylgroups; the halomethyl groups or hydroxymethyl groups can be present onthe same polymer bearing the phenolic groups or on a different polymer,or on a monomeric species present with the phenolic group substitutedpolymer; maleimide groups, such as those of the formula

[0160] biphenylene groups, such as those of the formula

[0161] 5-norbornene-2,3-dicarboximido (nadimido) groups, such as thoseof the formula

[0162] alkylcarboxylate groups, such as those of the formula

[0163] wherein R is an alkyl group (including saturated, unsaturated,and cyclic alkyl groups), preferably with from 1 to about 30 carbonatoms, more preferably with from 1 to about 6 carbon atoms, asubstituted alkyl group, an aryl group, preferably with from 6 to about30 carbon atoms, more preferably with from 1 to about 2 carbon atoms, asubstituted aryl group, an arylalkyl group, preferably with from 7 toabout 35 carbon atoms, more preferably with from 7 to about 15 carbonatoms, or a substituted arylalkyl group, wherein the substituents on thesubstituted alkyl, aryl, and arylalkyl groups can be (but are notlimited to) alkoxy groups, preferably with from 1 to about 6 carbonatoms, aryloxy groups, preferably with from 6 to about 24 carbon atoms,arylalkyloxy groups, preferably with from 7 to about 30 carbon atoms,hydroxy groups, amine groups, imine groups, ammonium groups, pyridinegroups, pyridinium groups, ether groups, ester groups, amide groups,carbonyl groups, thiocarbonyl groups, sulfate groups, sulfonate groups,sulfide groups, sulfoxide groups, phosphine groups, phosphonium groups,phosphate groups, mercapto groups, nitroso groups, sulfone groups, acylgroups, acid anhydride groups, azide groups, and the like, wherein twoor more substituents can be joined together to form a ring, and thelike.

[0164] The thermal sensitivity imparting groups can be present either asterminal end groups on the polymer or as groups which are pendant fromone or more monomer repeat units within the polymer chain. When thethermal sensitivity imparting groups are present as terminal end groups,one or both polymer ends can be terminated with the thermal sensitivityimparting group (or more, if the polymer is crosslinked and has morethan two termini). When the thermal sensitivity imparting groups aresubstituents on one or more monomer repeat units of the polymer, anydesired or suitable degree of substitution can be employed. Preferably,the degree of substitution is from about 1 to about 4 thermalsensitivity imparting groups per repeat monomer unit, although thedegree of substitution can be outside this range. Preferably, the degreeof substitution is from about 0.5 to about 5 milliequivalents of thermalsensitivity imparting group per gram of polymer, and more preferablyfrom about 0.75 to about 1.5 milliequivalents per gram, although thedegree of substitution can be outside this range.

[0165] The thermal sensitivity imparting groups can be placed on thepolymer by any suitable or desired synthetic method. Processes forputting the above mentioned thermal sensitivity imparting groups onpolymers are disclosed in, for example, “Polyimides,” C. E. Sroog, Prog.Polym. Sci., Vol. 16, 561-694 (1991); F. E. Arnold and L. S. Tan,Symposium on Recent Advances in Polyimides and Other High PerformancePolymers, Reno, Nev. (July 1987); L. S. Tan and F. E. Arnold, J. Polym.Sci. Part A, 26, 1819 (1988); U.S. Pat. Nos. 4,973,636; and 4,927,907;the disclosures of each of which are totally incorporated herein byreference.

[0166] Other procedures for placing thermally curable end groups onaromatic polymers are disclosed in, for example, P. M. Hergenrother, J.Macromol. Sci. Rev. Macromol. Chem., C19 (1), 1-34 (1980); V. Percec andB. C. Auman, Makromol. Chem., 185, 2319 (1984); S. J. Havens, and P. M.Hergenrother, J. of Polymer Science: Polymer Chemistry Edition, 22, 3011(1984); P. M. Hergenrother, J. of Polymer Science: Polymer ChemistryEdition, 20, 3131 (1982); V. Percec, P. L. Rinaldi, and B. C. Auman,Polymer Bulletin, 10, 215 (1983); “Functional Polymers and SequentialCopolymers by Phase Transfer Catalysis, 2. Synthesis andCharacterization of Aromatic Poly(ether sulfones Containing Vinylbenzyland Ethynylbenzyl Chain Ends,” V. Percec and B. C. Auman, Makromol.Chem. 185, 1867 (1984); “Functional Polymers and Sequential Copolymersby Phase Transfer Catalysis, 6. On the Phase Transfer CatalyzedWilliamson Polyetherification as a New Method for the Preparation ofAlternating Block copolymers,” V. Percec, B. Auman, and P. L. Rinaldi,Polymer Bulletin, 10, 391 (1983); “Functional Polymers and SequentialCopolymers by Phase Transfer Catalysis, 3 Synthesis and Characterizationof Aromatic Poly(ether sulfone)s andPoly(oxy-2,6-dimethyl-1,4-phenylene) Containing Pendant Vinyl Groups,”V. Percec and B. C. Auman, Makromol. Chem., 185, 2319 (1984); and “PhaseTransfer Catalysis, Functional Polymers and Sequential Copolymers byPTC,5. Synthesis and Characterization of Polyformals of PolyetherSulfones,” Polymer Bulletin, 10, 385 (1983); the disclosures of each ofwhich are totally incorporated herein by reference.

[0167] In some instances a functional group can behave as either aphotosensitivity-imparting group or a thermal sensitivity impartinggroup. For the polymers of the present invention having optional thermalsensitivity imparting groups thereon, at least two different groups arepresent on the polymer, one of which functions as aphotosensitivity-imparting group and one of which functions as a thermalsensitivity imparting group. Either the two groups are selected so thatthe thermal sensitivity imparting group does not react or crosslink whenexposed to actinic radiation at a level to which thephotosensitivity-imparting group is sensitive, or photocuring is haltedwhile at least some thermal sensitivity imparting groups remain intactand unreacted or uncrosslinked on the polymer. Typically (although notnecessarily) the thermal sensitivity imparting group is one which reactsat a temperature in excess of the glass transition temperature of thepolymer subsequent to crosslinking or chain extension via photoexposure.

[0168] When thermal sensitivity imparting groups are present, thepolymers of the present invention are cured in a two-stage process whichentails (a) exposing the polymer to actinic radiation, thereby causingthe polymer to become crosslinked or chain extended through thephotosensitivity-imparting groups; and (b) subsequent to step (a),heating the polymer to a temperature of at least 140° C., therebycausing further crosslinking or chain extension of the polymer throughthe thermal sensitivity imparting groups.

[0169] The temperature selected for the second, thermal cure stepgenerally depends on the thermal sensitivity imparting group which ispresent on the polymer. For example, ethynyl groups preferably are curedat temperatures of from about 150 to about 300° C. Halomethyl groupspreferably are cured at temperatures of from about 150 to about 260° C.Hydroxymethyl groups preferably are cured at temperatures of from about150 to about 250° C. Phenylethynyl phenyl groups preferably are cured attemperatures of about 350° C. Vinyl groups preferably are cured attemperatures of from about 150 to about 250° C. Allyl groups preferablyare cured at temperatures of over about 260° C. Epoxy groups preferablyare cured at temperatures of about 150° C. Maleimide groups preferablyare cured at temperatures of from about 300 to about 350° C.Benzocyclobutene groups preferably are cured at temperatures of overabout 300° C. 5-Norbornene-2,3-dicarboximido groups preferably are curedat temperatures of from about 250 to about 350° C. Vinyl ether groupspreferably are cured at temperatures of about 150° C. Phenolic groups inthe presence of hydroxymethyl or halomethyl groups preferably are curedat temperatures of from about 150 to about 180° C. Alkylcarboxylategroups preferably are cured at temperatures of from about 150 to about250° C. Curing temperatures usually do not exceed 350 or 400° C.,although higher temperatures can be employed provided that decompositionof the polymer does not occur. Higher temperature cures preferably takeplace in an oxygen-excluded environment.

[0170] Reaction of the phenylethynyl end groups serves to chain-extendthe network. Hydroxymethyl and halo groups are also preferred when thephotopatternable polymer has a glass transition temperature of less thanabout 150° C. Hydroxymethyl and halomethyl groups on phenolic ends areparticularly reactive and serve to chain-extend the network. The factthat this chain extension occurs at temperatures significantly in excessof the glass transition temperature of the polymer facilitates the chainextension reaction, relaxes stresses in the crosslinked film, and allowsfor the extrusion of thermally labile alkyl fragments introduced in thephotoactivation of the backbone. Phenolic end groups can be obtained byadjusting the stoichiometry of the coupling reaction in the formation ofpolyarylene ether ketones; for example, excess bisphenol A is used whenbisphenol A is the B group. Halomethyl groups are particularlypreferred. Halomethyl groups react at a temperature in excess of 150° C.and extensively crosslink the polymer by the elimination of hydrochloricacid and the formation of methylene bridges. When the photoexposedcrosslinked polymer has a glass transition temperature of less thanabout 150° C., halomethyl groups are particularly preferred. The factthat this chain extension and crosslinking occurs at temperaturessignificantly in excess of the glass transition temperature of thepolymer facilitates the chain extension reaction, relaxes stresses inthe cross-linked film, and allows for the extrusion of thermally labilealkyl fragments introduced in the photoactivation of the backbone. Thethermal reaction is believed to eliminate hydrohalic acid and to linkpolymer chains with methylene bridges. Crosslinking of the halomethylgroups begins near 150° C. and proceeds rapidly in the temperature rangeof from about 180 to about 210° C.

[0171] Further information regarding photoresist compositions isdisclosed in, for example, J. J. Zupancic, D. C. Blazej, T. C. Baker,and E. A. Dinkel, Polymer Preprints, 32, (2), 178 (1991); “HighPerformance Electron Negative Resist, Chloromethylated Polystyrene. AStudy on Molecular Parameters,” S. Imamura, T. Tamamura, and K. Harada,J. of Applied Polymer Science, 27, 937 (1982); “ChloromethylatedPolystyrene as a Dry Etching-Resistant Negative Resist for SubmicronTechnology”, S. Imamura, J. Electrochem. Soc.: Solid-state Science andTechnology, 126(9), 1628 (1979); “UV curing of composites based onmodified unsaturated polyesters,” W. Shi and B. Ranby, J. of AppliedPolymer Science, Vol. 51, 1129 (1994); “Cinnamates VI. Light-SensitivePolymers with Pendant o-, m- and p-hydroxycinnamate Moieties,” F.Scigalski, M. Toczek, and J. Paczkowski, Polymer, 35, 692 (1994); and“Radiation-cured Polyurethane Methacrylate Pressure-sensitiveAdhesives,” G. Ansell and C. Butler, Polymer, 35 (9), 2001 (1994), thedisclosures of each of which are totally incorporated herein byreference.

[0172] In some instances, the terminal groups on the polymer can beselected by the stoichiometry of the polymer synthesis. For example,when a polymer is prepared by the reaction of 4,4′-dichlorobenzophenoneand bis-phenol A in the presence of potassium carbonate inN,N-dimethylacetamide, if the bis-phenol A is present in about 7.5 to 8mole percent excess, the resulting polymer generally is bis-phenolA-terminated (wherein the bis-phenol A moiety may or may not have one ormore hydroxy groups thereon), and the resulting polymer typically has apolydispersity (M_(w)/M_(n)) of from about 2 to about 3.5. When thebis-phenol A-terminated polymer is subjected to further reactions toplace functional groups thereon, such as haloalkyl groups, and/or toconvert one kind of functional group, such as a haloalkyl group, toanother kind of functional group, such as an unsaturated ester group,the polydispersity of the polymer can rise to the range of from about 4to about 6. In contrast, if the 4,4′-dichlorobenzophenone is present inabout 7.5 to 8 mole percent excess, the reaction time is approximatelyhalf that required for the bis-phenol A excess reaction, the resultingpolymer generally is benzophenone-terminated (wherein the benzophenonemoiety may or may not have one or more chlorine atoms thereon), and theresulting polymer typically has a polydispersity of from about 2 toabout 3.5. When the benzophenone-terminated polymer is subjected tofurther reactions to place functional groups thereon, such as haloalkylgroups, and/or to convert one kind of functional group, such as ahaloalkyl group, to another kind of functional group, such as anunsaturated ester group, the polydispersity of the polymer typicallyremains in the range of from about 2 to about 3.5. Similarly, when apolymer is prepared by the reaction of 4,4′-difluorobenzophenone witheither 9,9′-bis(4-hydroxyphenyl)fluorene or bis-phenol A in the presenceof potassium carbonate in N,N-dimethylacetamide, if the4,4′-difluorobenzophenone reactant is present in excess, the resultingpolymer generally has benzophenone terminal groups (which may or may nothave one or more fluorine atoms thereon). The well-known Carothersequation can be employed to calculate the stoichiometric offset requiredto obtain the desired molecular weight. (See, for example, William H.Carothers, “An Introduction to the General Theory of CondensationPolymers,” Chem. Rev., 8, 353 (1931) and J. Amer. Chem. Soc., 51, 2548(1929); see also P. J. Flory, Principles of Polymer Chemistry, CornellUniversity Press, Ithaca, N.Y. (1953); the disclosures of each of whichare totally incorporated herein by reference.) More generally speaking,during the preparation of polymers of the formula

[0173] the stoichiometry of the polymer synthesis reaction can beadjusted so that the end groups of the polymer are derived from the “A”groups or derived from the “B” groups. Specific functional groups canalso be present on these terminal “A” groups or “B” groups, such asethynyl groups or other thermally sensitive groups, hydroxy groups whichare attached to the aromatic ring on an “A” or “B” group to form aphenolic moiety, halogen atoms which are attached to the “A” or “B”group, or the like.

[0174] Polymers with end groups derived from the “A” group, such asbenzophenone groups or halogenated benzophenone groups, may be preferredfor some applications because both the syntheses and some of thereactions of these materials to place substituents thereon may be easierto control and may yield better results with respect to, for example,cost, molecular weight, molecular weight range, and polydispersity(M_(w)/M_(n)) compared to polymers with end groups derived from the “B”group, such as bis-phenol A groups (having one or more hydroxy groups onthe aromatic rings thereof) or other phenolic groups. While not beinglimited to any particular theory, it is believed that the haloalkylationreaction in particular proceeds most rapidly on the phenolic tails whenthe polymer is bis-phenol A terminated. Moreover, it is believed thathalomethylated groups on phenolic-terminated polymers may beparticularly reactive to subsequent crosslinking or chain extension. Incontrast, it is generally believed that halomethylation does not takeplace on the terminal aromatic groups with electron withdrawingsubstituents, such as benzophenone, halogenated benzophenone, or thelike. The “A” group terminated materials may also function as anadhesive, and in applications such as thermal ink jet printheads, theuse of the crosslinked “A” group terminated polymer may reduce oreliminate the need for an epoxy adhesive to bond the heater plate to thechannel plate.

[0175] If desired, to reduce the amount of residual halogen in aphotoresist or other composition containing the polymers of the presentinvention, thereby also reducing or eliminating the generation ofhydrohalic acid during a subsequent thermal curing step, any residualhalogen atoms or haloalkyl groups on the photopatternable polymer can beconverted to methoxy groups, hydroxide groups, acetoxy groups, aminegroups, or the like by any desired process, including those processesdisclosed hereinabove, those disclosed in, for example, British Pat. No.863,702, Chem Abstr. 55, 18667b (1961), and other publicationspreviously incorporated herein by reference, and the like.

[0176] The photopatternable polymer can be cured by uniform exposure toactinic radiation at wavelengths and/or energy levels capable of causingcrosslinking or chain extension of the polymer through thephotosensitivity-imparting groups. Alternatively, the photopatternablepolymer is developed by imagewise exposure of the material to radiationat a wavelength and/or at an energy level to which thephotosensitivity-imparting groups are sensitive. Typically, aphotoresist composition will contain the photopatternable polymer, anoptional solvent for the photopatternable polymer, an optionalsensitizer, and an optional photoinitiator. Solvents may be particularlydesirable when the uncrosslinked photopatternable polymer has a highT_(g). The solvent and photopatternable polymer typically are present inrelative amounts of from 0 to about 99 percent by weight solvent andfrom about 1 to 100 percent polymer, preferably are present in relativeamounts of from about 20 to about 60 percent by weight solvent and fromabout 40 to about 80 percent by weight polymer, and more preferably arepresent in relative amounts of from about 30 to about 60 percent byweight solvent and from about 40 to about 70 percent by weight polymer,although the relative amounts can be outside these ranges.

[0177] Sensitizers absorb light energy and facilitate the transfer ofenergy to unsaturated bonds which can then react to crosslink or chainextend the resin. Sensitizers frequently expand the useful energywavelength range for photoexposure, and typically are aromatic lightabsorbing chromophores. Sensitizers can also lead to the formation ofphotoinitiators, which can be free radical or ionic. When present, theoptional sensitizer and the photopatternable polymer typically arepresent in relative amounts of from about 0.1 to about 20 percent byweight sensitizer and from about 80 to about 99.9 percent by weightphotopatternable polymer, and preferably are present in relative amountsof from about 1 to about 10 percent by weight sensitizer and from about90 to about 99 percent by weight photopatternable polymer, although therelative amounts can be outside these ranges.

[0178] Photoinitiators generally generate ions or free radicals whichinitiate polymerization upon exposure to actinic radiation. Whenpresent, the optional photoinitiator and the photopatternable polymertypically are present in relative amounts of from about 0.1 to about 20percent by weight photoinitiator and from about 80 to about 99.9 percentby weight photopatternable polymer, and preferably are present inrelative amounts of from about 1 to about 10 percent by weightphotoinitiator and from about 90 to about 99 percent by weightphotopatternable polymer, although the relative amounts can be outsidethese ranges.

[0179] A single material can also function as both a sensitizer and aphotoinitiator.

[0180] Examples of specific sensitizers and photoinitiators includeMichler's ketone (Aldrich Chemical Co.), Darocure 1173, Darocure 4265,Irgacure 184, Irgacure 261, and Irgacure 907 (available from Ciba-Geigy,Ardsley, N.Y.), and mixtures thereof. Further background material oninitiators is disclosed in, for example, Ober et al., J.M.S.—Pure Appl.Chem., A30 (12), 877-897 (1993); G. E. Green, B. P. Stark, and S. A.Zahir, “Photocrosslinkable Resin Systems,” J. Macro. Sci. Revs. Macro.Chem., C21(2), 187 (1981); H. F. Gruber, “Photoinitiators for FreeRadical Polymerization,” Prog. Polym. Sci., Vol. 17, 953 (1992); JohannG. Kloosterboer, “Network Formation by Chain CrosslinkingPhotopolymerization and Its Applications in Electronics,” Advances inPolymer Science, 89, Springer-Verlag Berlin Heidelberg (1988); and“Diaryliodonium Salts as Thermal Initiators of Cationic Polymerization,”J. V. Crivello, T. P. Lockhart, and J. L. Lee, J. of Polymer Science:Polymer Chemistry Edition, 21, 97 (1983), the disclosures of each ofwhich are totally incorporated herein by reference. Sensitizers areavailable from, for example, Aldrich Chemical Co., Milwaukee, Wis., andPfaltz and Bauer, Waterberry, Conn. Benzophenone and its derivatives canfunction as photosensitizers. Triphenylsulfonium and diphenyl iodoniumsalts are examples of typical cationic photoinitiators.

[0181] The photoresist containing the allyl ether substituted polymer isdeveloped by imagewise exposure of the material to radiation at awavelength to which it is sensitive. While not being limited to anyparticular theory, it is believed that exposure to, for example,ultraviolet radiation generally opens the ethylenic linkage in the allylether groups and leads to crosslinking or chain extension at the “long”bond sites as shown below:

[0182] Alternatively, one specific example of a class of suitablesensitizers or initiators for the allyl-substituted polymers is that ofbis(azides), of the general formula

[0183] wherein R is

[0184] or

[0185] wherein R₁, R₂, R₃, and R₄ each, independently of the others, isa hydrogen atom, an alkyl group, including saturated, unsaturated, andcyclic alkyl groups, preferably with from 1 to about 30 carbon atoms,and more preferably with from 1 to about 6 carbon atoms, a substitutedalkyl group, an aryl group, preferably with from 6 to about 18 carbonatoms, and more preferably with about 6 carbon atoms, a substituted arylgroup, an arylalkyl group, preferably with from 7 to about 48 carbonatoms, and more preferably with from about 7 to about 8 carbon atoms, ora substituted arylalkyl group, and x is 0 or 1, wherein the substituentson the substituted alkyl, aryl, and aryl groups can be (but are notlimited to) alkyl groups, including saturated, unsaturated, linear,branched, and cyclic alkyl groups, preferably with from 1 to about 6carbon atoms, substituted alkyl groups, preferably with from 1 to about6 carbon atoms, aryl groups, preferably with from 6 to about 24 carbonatoms, substituted aryl groups, preferably with from 6 to about 24carbon atoms, arylalkyl groups, preferably with from 7 to about 30carbon atoms, substituted arylalkyl groups, preferably with from 7 toabout 30 carbon atoms, alkoxy groups, preferably with from 1 to about 6carbon atoms, substituted alkoxy groups, preferably with from 1 to about6 carbon atoms, aryloxy groups, preferably with from 6 to about 24carbon atoms, substituted aryloxy groups, preferably with from 6 toabout 24 carbon atoms, arylalkyloxy groups, preferably with from 7 toabout 30 carbon atoms, substituted arylalkyloxy groups, preferably withfrom 7 to about 30 carbon atoms, amine groups, imine groups, ammoniumgroups, pyridine groups, pyridinium groups, ether groups, ester groups,amide groups, carbonyl groups, thiocarbonyl groups, sulfate groups,sulfonate groups, sulfide groups, sulfoxide groups, phosphine groups,phosphonium groups, phosphate groups, mercapto groups, nitroso groups,sulfone groups, acyl groups, acid anhydride groups, azide groups, andthe like, wherein the substituents on the substituted alkyl groups,substituted aryl groups, substituted arylalkyl groups, substitutedalkoxy groups, substituted aryloxy groups, and substituted arylalkyloxygroups can be (but are not limited to) hydroxy groups, amine groups,imine groups, ammonium groups, pyridine groups, pyridinium groups, ethergroups, aldehyde groups, ketone groups, ester groups, amide groups,carboxylic acid groups, carbonyl groups, thiocarbonyl groups, sulfategroups, sulfonate groups, sulfide groups, sulfoxide groups, phosphinegroups, phosphonium groups, phosphate groups, cyano groups, nitrilegroups, mercapto groups, nitroso groups, halogen atoms, nitro groups,sulfone groups, acyl groups, acid anhydride groups, azide groups,mixtures thereof, and the like, wherein any two or more substituents canbe joined together to form a ring. Examples of suitable bis(azides)include 4,4′-diazidostilbene, of the formula

[0186] 4,4′-diazidobenzophenone, of the formula

[0187] 2,6-di-(4′-azidobenzal)-4-methylcyclohexanone, of the formula

[0188] 4,4′-diazidobenzalacetone, of the formula

[0189] and the like. While not being limited to any particular theory,it is believed that exposure to, for example, ultraviolet radiationenables curing, as illustrated below

[0190] The photoresist containing the epoxidized polymer is developed byimagewise exposure of the material to radiation at a wavelength to whichit is sensitive. While not being limited to any particular theory, it isbelieved that exposure to, for example, ultraviolet radiation generallycauses generation of acidic species by the initiator, followed byreaction of the acidic species with the epoxy groups to cause ringopening and crosslinking or chain extension at the “long” bond sites asshown below:

[0191] Inhibitors may also optionally be present in the photoresistcontaining the photopatternable polymer. Examples of suitable inhibitorsinclude MEHQ, a methyl ether of hydroquinone, of the formula

[0192] t-butylcatechol, of the formula

[0193] hydroquinone, of the formula

[0194] and the like, the inhibitor typically present in an amount offrom about 500 to about 1,500 parts per million by weight of aphotoresist solution containing about 40 percent by weight polymersolids, although the amount can be outside this range.

[0195] Amine curing of the epoxidized polymer is also possible, withcuring occurring upon the application of heat. While not being limitedto any particular theory, it is believed that the curing scheme in oneexample is as follows:

[0196] In another preferred embodiment of the present invention, aphotoresist is prepared which comprises a mixture of the polymersubstituted with photoactive groups, such as epoxy groups, and thehalomethylated polymer. The halomethylated polymer, which can be used asan intermediate in the synthesis of the photosensitivity-imparting groupsubstituted polymer, also functions as an accelerator which generatesfree radicals upon exposure to ultraviolet light, and thus can be usedinstead of or in addition to other accelerators or sensitizers, such asMichler's ketone or the like. In addition, the substitution of thehalomethylated precursor with the photosensitivity-imparting groups canbe controlled so as to yield a mixture containing a known proportion ofthe halomethyl residue. Accordingly, a photoresist can be prepared ofthe photosensitivity-imparting group substituted polymer without theneed to add an additional initiator to the precursor material.Typically, the halomethylated polymer (which typically is substituted toa degree of from about 0.25 to about 2.0 halomethyl groups per monomerrepeat unit, preferably from about 1 to about 2 halomethyl groups permonomer repeat unit, and more preferably from about 1.5 to about 2halomethyl groups per monomer repeat unit) and thephotosensitivity-imparting group substituted polymer (which typically issubstituted to a degree of from about 0.25 to about 2.0photosensitivity-imparting groups per monomer repeat unit, preferablyfrom about 0.5 to about 1 photosensitivity-imparting group per monomerrepeat unit, and more preferably from about 0.7 to about 0.8photosensitivity-imparting group per monomer repeat unit) are present inrelative amounts such that the degree of substitution when measured forthe blended composition is from about 0.25 to about 1.5, preferably fromabout 0.5 to about 0.8, and more preferably about 0.75photosensitivity-imparting groups per monomer repeat unit, and fromabout 0.25 to about 2.25, preferably from about 0.75 to about 2, andmore preferably from about 0.75 to about 1 halomethyl group per monomerrepeat unit, although the relative amounts can be outside these ranges.Similarly, a polymer substituted with both halomethyl andphotosensitivity-imparting groups can function as an accelerator. Inthis instance, the accelerating polymer typically exhibits a degree ofsubstitution of from about 0.25 to about 1.5, preferably from about 0.5to about 0.8, and more preferably about 0.75 photosensitivity-impartinggroups per monomer repeat unit, and from about 0.25 to about 2.25,preferably from about 0.75 to about 2, and more preferably from about0.75 to about 1 halomethyl group per monomer repeat unit, although therelative amounts can be outside these ranges.

[0197] Particularly preferred as reaction accelerators are polymers ofthe formula

[0198] wherein A is selected so that the monomeric unit contains abenzophenone moiety and x and B are as defined hereinabove, said polymerhaving at least one halomethyl substituent per monomer repeat unit in atleast some of the monomer repeat units of the polymer, said polymerhaving at least one photosensitivity-imparting group per monomer repeatunit in at least some of the monomer repeat units of the polymer.Examples of suitable A groups for this embodiment include

[0199] and the like. While not being limited to any particular theory,it is believed that in this embodiment, the presence of the benzophenonemoiety acts as a photoabsorbing element in the polymer backbone andcontributes to the photoinitiating characteristics of the polymer. Inthis embodiment, advantages include high sensitivity, highdevelopability, and high aspect ratios in thick films.

[0200] When the halomethylated polymer is present in relatively highconcentrations in a photoresist with respect to the amount ofphotosensitivity-imparting group substituted polymer, the halomethylatedmaterial can also act as an ultraviolet polymerization inhibitor.

[0201] Many of the photosensitivity-imparting groups which are indicatedabove as being capable of enabling crosslinking or chain extension ofthe polymer upon exposure to actinic radiation can also enablecrosslinking or chain extension of the polymer upon exposure to elevatedtemperatures; thus the polymers of the present invention can also, ifdesired, be used in applications wherein thermal curing is employed.

[0202] In all of the above reactions and substitutions illustrated abovefor the polymer of the formula

[0203] it is to be understood that analogous reactions and substitutionswill occur for the polymer of the formula

[0204] The precise degree of photosensitivity-imparting groupsubstitution of the polymer may be difficult to control, and differentbatches of photosensitivity-imparting group substituted polymers mayhave somewhat different degrees of substitution even though the batcheswere prepared under similar conditions. Photoresist compositionscontaining polymers for which the degree of photosensitivity-impartinggroup substitution varies will exhibit variation in characteristics suchas photospeed, imaging energy requirements, photosensitivity, shelflife, film forming characteristics, development characteristics, and thelike. Accordingly, if desired, the photoresist composition can beformulated from a mixture of (A) a first component comprising a polymer,at least some of the monomer repeat units of which have at least onephotosensitivity-imparting group thereon, said polymer having a firstdegree of photosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram and beingof the above general formula; and (B) a second component which compriseseither (1) a polymer having a second degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram lower thanthe first degree of photosensitivity-imparting group substitution,wherein said second degree of photosensitivity-imparting groupsubstitution may be zero, wherein the mixture of the first component andthe second component has a third degree of photosensitivity-impartinggroup substitution measured in milliequivalents ofphotosensitivity-imparting group per gram which is lower than the firstdegree of photosensitivity-imparting group substitution and higher thanthe second degree of photosensitivity-imparting group substitution, or(2) a reactive diluent having at least one photosensitivity-impartinggroup per molecule and having a fourth degree ofphotosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram, whereinthe mixture of the first component and the second component has a fifthdegree of photosensitivity-imparting group substitution measured inmilliequivalents of photosensitivity-imparting group per gram which ishigher than the first degree of photosensitivity-imparting groupsubstitution and lower than the fourth degree ofphotosensitivity-imparting group substitution; wherein the weightaverage molecular weight of the mixture typically is from about 10,000to about 50,000, preferably from about 10,000 to about 35,000, and morepreferably from about 10,000 to about 25,000, although the weightaverage molecular weight of the blend can be outside these ranges; andwherein the third or fifth degree of photosensitivity-imparting groupsubstitution typically is from about 0.25 to about 2 milliequivalents ofphotosensitivity-imparting group per gram of mixture, preferably 0.8 toabout 1.4 milliequivalents of photosensitivity-imparting groups per gramof mixture, although the degree of substitution can be outside theseranges.

[0205] The first photosensitivity-imparting group substituted polymercan be prepared as described hereinabove. In one embodiment of thepresent invention, the second component is a polymer which either issubstituted with photosensitivity-imparting groups but to a lesserdegree than the first polymer, or which does not containphotosensitivity-imparting group substituents. The second polymer may beselected from a wide variety of polymers. For example, in one embodimentof the present invention, two different photosensitivity-imparting groupsubstituted polymers are blended together, wherein one has a higherdegree of substitution than the other. In another embodiment of thepresent invention, the second polymer is a polymer of the above generalformula but having no photosensitivity-imparting group substituents,such as the polymer starting materials (and, if deep ultraviolet, x-ray,or electron beam radiation are not being used for photoexposure, thehaloalkylated polymers prepared as described hereinabove). In yetanother embodiment of the present invention, the second polymer is notnecessarily a polymer of the above general formula, but is selected fromany of a wide variety of other high performance polymers suitable forobtaining a desirable photoresist mixture with the desiredcharacteristics, such as epoxies, polycarbonates, diallyl phthalates,chloromethylated bis-fluorenones, polyphenylenes, phenoxy resins,polyarylene ethers, poly (ether imides), polyarylene ether ketones,polyphenylene sulfides, polysulfones, poly (ether sulfones), polyphenyltriazines, polyimides, polyphenyl quinoxalines, other polyheterocyclicsystems, and the like, as well as mixtures thereof. High performancepolymers typically are moldable at temperatures above those at whichtheir use is intended, and are useful for high temperature structuralapplications. While most high performance polymers are thermoplastic,some, such as phenolics, tend to be thermosetting. Any combination ofphotosensitivity-imparting group substituted polymers of the aboveformula, polymers having no photosensitivity-imparting groupsubstituents but falling within the above general formula, and/or otherpolymers outside the scope of the above general formula can be used asthe second polymer for the present invention. For example, in oneembodiment of the present invention, a photoresist is prepared from: (a)60 parts by weight of a polyarylene ether ketone within the abovegeneral formula having 1 chloromethyl group per repeating monomer unit,1 acrylate group per repeating monomer unit, and a number averagemolecular weight of 60,000; (b) 40 parts by weight of a polyaryleneether ketone resin within the above general formula but having nosubstituents thereon, with a number average molecular weight of 2,800and a polydispersity (M_(w)/M_(n)) of about 2.5; and (c) 10 parts byweight of EPON 1001 adhesive resin (Shell Chemical Company, Houston,Tex.). This mixture has a degree of acryloylation of about 1.1milliequivalents of acrylate per gram of resin solids and a weightaverage molecular weight of 34,000. Typically, when a photoresist isprepared from a mixture of an unsaturated ester substituted polymer ofthe above general formula and a second polymer having no unsaturatedester groups, a photoresist solution containing about 40 percent byweight polymer solids will contain from 10 to about 25 parts by weightof a polymer having unsaturated ester substituents and from about 10 toabout 25 parts by weight of a polymer having no unsaturated estersubstituents.

[0206] Alternatively, the second component can be a reactive diluent. Insome embodiments, the reactive diluent is a liquid, and can replace asolvent when the photopatternable polymer is too high in viscosity to becured without solvents. In other embodiments, the reactive diluent is asolid. The reactive diluent has functional groups which are capable ofpolymerizing when the reactive diluent is exposed to actinic radiationat an energy or wavelength level which is capable of inducingcrosslinking or chain extension in the photopatternable polymer.Reactive diluents preferably are monomeric or oligomeric, and include(but are not limited to) mono-, di-, tri-, and multi-functionalunsaturated ester monomers and the like. Examples of suitable reactivediluents include monoacrylates, such as cyclohexyl acrylate, 2-ethoxyethyl acrylate, 2-methoxy ethyl acrylate, 2(2-ethoxyethoxy) ethylacrylate, stearyl acrylate, tetrahydrofurfuryl acrylate, octyl acrylate,lauryl acrylate, behenyl acrylate, 2-phenoxy ethyl acrylate, tertiarybutyl acrylate, glycidyl acrylate, isodecyl acrylate, benzyl acrylate,hexyl acrylate, isooctyl acrylate, isobornyl acrylate, butanediolmonoacrylate, ethoxylated phenol monoacrylate, oxyethylated phenolacrylate, monomethoxy hexanediol acrylate, β-carboxy ethyl acrylate,dicyclopentyl acrylate, carbonyl acrylate, octyl decyl acrylate,ethoxylated nonylphenol acrylate, hydroxyethyl acrylate, hydroxyethylmethacrylate, and the like, diacrylates, such as 1,3-butylene glycoldiacrylate, 1,4-butanediol diacrylate, diethylene glycol diacrylate,1,6-hexanediol diacrylate, tetraethylene glycol diacrylate, triethyleneglycol diacrylate, tripropylene glycol diacrylate, polybutanedioldiacrylate, polyethylene glycol diacrylate, propoxylated neopentylglycol diacrylate, ethoxylated neopentyl glycol diacrylate,polybutadiene diacrylate, and the like, polyacrylates, such astrimethylol propane triacrylate, pentaerythritol tetraacrylate,pentaerythritol triacrylate, dipentaerythritol pentaacrylate, glycerolpropoxy triacrylate, tris(2-hydroxyethyl) isocyanurate triacrylate,pentaacrylate ester, and the like, epoxy acrylates, polyester acrylates,polyether polyol acrylates, urethane acrylates, amine acrylates, acrylicacrylates, and the like. Mixtures of two or more materials can also beemployed as the reactive diluent. Suitable reactive diluents arecommercially available from, for example, Sartomer Co., Inc., HenkelCorp., Radcure Specialties, and the like. When the second component is areactive diluent, typically, the first and second components are presentin relative amounts of from about 5 to about 50 percent by weightreactive diluent (second component) and from about 50 to about 95percent by weight polymer (first component), and preferably in relativeamounts of from about 10 to about 20 percent by weight reactive diluent(second component) and from about 80 to about 90 percent by weightpolymer (first component), although the relative amounts can be outsidethese ranges.

[0207] If desired, to reduce the amount of residual halogen in aphotoresist or other composition containing the polymers of the presentinvention, thereby also reducing or eliminating the generation ofhydrohalic acid during a subsequent thermal curing step, any residualhaloalkyl groups on the photopatternable polymer can be converted tomethoxy groups, hydroxide groups, acetoxy groups, amine groups, or thelike by any desired process, including those processes disclosedhereinabove, those disclosed in, for example, British Pat. No. 863,702,Chem Abstr. 55, 18667b (1961), and other publications previouslyincorporated herein by reference, and the like.

[0208] Photopatternable epoxidized polymers prepared by the process ofthe present invention can be used as components in ink jet printheads.The printheads of the present invention can be of any suitableconfiguration. An example of a suitable configuration, suitable in thisinstance for thermal ink jet printing, is illustrated schematically inFIG. 1, which depicts an enlarged, schematic isometric view of the frontface 29 of a printhead 10 showing the array of droplet emitting nozzles27. Referring also to FIG. 2, discussed later, the lower electricallyinsulating substrate or heating element plate 28 has the heatingelements 34 and addressing electrodes 33 patterned on surface 30thereof, while the upper substrate or channel plate 31 has parallelgrooves 20 which extend in one direction and penetrate through the uppersubstrate front face edge 29. The other end of grooves 20 terminate atslanted wall 21, the floor 41 of the internal recess 24 which is used asthe ink supply manifold for the capillary filled ink channels 20, has anopening 25 therethrough for use as an ink fill hole. The surface of thechannel plate with the grooves are aligned and bonded to the heaterplate 28, so that a respective one of the plurality of heating elements34 is positioned in each channel, formed by the grooves and the lowersubstrate or heater plate. Ink enters the manifold formed by the recess24 and the lower substrate 28 through the fill hole 25 and by capillaryaction, fills the channels 20 by flowing through an elongated recess 38formed in the thick film insulative layer 18. The ink at each nozzleforms a meniscus, the surface tension of which prevents the ink fromweeping therefrom. The addressing electrodes 33 on the lower substrateor channel plate 28 terminate at terminals 32. The upper substrate orchannel plate 31 is smaller than that of the lower substrate in orderthat the electrode terminals 32 are exposed and available for wirebonding to the electrodes on the daughter board 19, on which theprinthead 10 is permanently mounted. Layer 18 is a thick filmpassivation layer, discussed later, sandwiched between the upper andlower substrates. This layer is etched to expose the heating elements,thus placing them in a pit, and is etched to form the elongated recessto enable ink flow between the manifold 24 and the ink channels 20. Inaddition, the thick film insulative layer is etched to expose theelectrode terminals.

[0209] A cross sectional view of FIG. 1 is taken along view line 2-2through one channel and shown as FIG. 2 to show how the ink flows fromthe manifold 24 and around the end 21 of the groove 20 as depicted byarrow 23. As is disclosed in U.S. Pat. Nos. 4,638,337, 4,601,777, andRe. 32,572, the disclosures of each of which are totally incorporatedherein by reference, a plurality of sets of bubble generating heatingelements 34 and their addressing electrodes 33 can be patterned on thepolished surface of a single side polished (100) silicon wafer. Prior topatterning, the multiple sets of printhead electrodes 33, the resistivematerial that serves as the heating elements 34, and the common return35, the polished surface of the wafer is coated with an underglaze layer39 such as silicon dioxide, having a typical thickness of from about5,000 Angstroms to about 2 microns, although the thickness can beoutside this range. The resistive material can be a dopedpolycrystalline silicon, which can be deposited by chemical vapordeposition (CVD) or any other well known resistive material such aszirconium boride (ZrB₂). The common return and the addressing electrodesare typically aluminum leads deposited on the underglaze and over theedges of the heating elements. The common return ends or terminals 37and addressing electrode terminals 32 are positioned at predeterminedlocations to allow clearance for wire bonding to the electrodes (notshown) of the daughter board 19, after the channel plate 31 is attachedto make a printhead. The common return 35 and the addressing electrodes33 are deposited to a thickness typically of from about 0.5 to about 3microns, although the thickness can be outside this range, with thepreferred thickness being 1.5 microns.

[0210] If polysilicon heating elements are used, they may besubsequently oxidized in steam or oxygen at a relatively hightemperature, typically about 1,100° C. although the temperature can beabove or below this value, for a period of time typically of from about50 to about 80 minutes, although the time period can be outside thisrange, prior to the deposition of the aluminum leads, in order toconvert a small portion of the polysilicon to SiO₂. In such cases, theheating elements are thermally oxidized to achieve an overglaze (notshown) of SiO₂ with a thickness typically of from about 500 Angstroms toabout 1 micron, although the thickness can be outside this range, whichhas good integrity with substantially no pinholes.

[0211] In one embodiment, polysilicon heating elements are used and anoptional silicon dioxide thermal oxide layer 17 is grown from thepolysilicon in high temperature steam. The thermal oxide layer istypically grown to a thickness of from about 0.5 to about 1 micron,although the thickness can be outside this range, to protect andinsulate the heating elements from the conductive ink. The thermal oxideis removed at the edges of the polysilicon heating elements forattachment of the addressing electrodes and common return, which arethen patterned and deposited. If a resistive material such as zirconiumboride is used for the heating elements, then other suitable well knowninsulative materials can be used for the protective layer thereover.Before electrode passivation, a tantalum (Ta) layer (not shown) can beoptionally deposited, typically to a thickness of about 1 micron,although the thickness can be above or below this value, on the heatingelement protective layer 17 for added protection thereof against thecavitational forces generated by the collapsing ink vapor bubbles duringprinthead operation. The tantalum layer is etched off all but theprotective layer 17 directly over the heating elements using, forexample, CF₄/O₂ plasma etching. For polysilicon heating elements, thealuminum common return and addressing electrodes typically are depositedon the underglaze layer and over the opposing edges of the polysiliconheating elements which have been cleared of oxide for the attachment ofthe common return and electrodes.

[0212] For electrode passivation, a film 16 is deposited over the entirewafer surface, including the plurality of sets of heating elements andaddressing electrodes. The passivation film 16 provides an ion barrierwhich will protect the exposed electrodes from the ink. Examples ofsuitable ion barrier materials for passivation film 16 includepolyimide, plasma nitride, phosphorous doped silicon dioxide, materialsdisclosed herein as being suitable for insulative layer 18, and thelike, as well as any combinations thereof. An effective ion barrierlayer is generally achieved when its thickness is from about 1000Angstroms to about 10 microns, although the thickness can be outsidethis range. In 300 dpi printheads, passivation layer 16 preferably has athickness of about 3 microns, although the thickness can be above orbelow this value. In 600 dpi printheads, the thickness of passivationlayer 16 preferably is such that the combined thickness of layer 16 andlayer 18 is about 25 microns, although the thickness can be above orbelow this value. The passivation film or layer 16 is etched off of theterminal ends of the common return and addressing electrodes for wirebonding later with the daughter board electrodes. This etching of thesilicon dioxide film can be by either the wet or dry etching method.Alternatively, the electrode passivation can be by plasma depositedsilicon nitride (Si₃N₄).

[0213] Next, a thick film type insulative layer 18, of a polymericmaterial discussed in further detail herein, is formed on thepassivation layer 16, typically having a thickness of from about 10 toabout 100 microns and preferably in the range of from about 25 to about50 microns, although the thickness can be outside these ranges. Evenmore preferably, in 300 dpi printheads, layer 18 preferably has athickness of about 30 microns, and in 600 dpi printheads, layer 18preferably has a thickness of from about 20 to about 22 microns,although other thicknesses can be employed. The insulative layer 18 isphotolithographically processed to enable etching and removal of thoseportions of the layer 18 over each heating element (forming recesses26), the elongated recess 38 for providing ink passage from the manifold24 to the ink channels 20, and over each electrode terminal 32, 37. Theelongated recess 38 is formed by the removal of this portion of thethick film layer 18. Thus, the passivation layer 16 alone protects theelectrodes 33 from exposure to the ink in this elongated recess 38.Optionally, if desired, insulative layer 18 can be applied as a seriesof thin layers of either similar or different composition. Typically, athin layer is deposited, photoexposed, partially cured, followed bydeposition of the next thin layer, photoexposure, partial curing, andthe like. The thin layers constituting thick film insulative layer 18contain a polymer of the formula indicated hereinabove. In oneembodiment of the present invention, a first thin layer is applied tocontact layer 16, said first thin layer containing a mixture of apolymer of the formula indicated hereinabove and an epoxy polymer,followed by photoexposure, partial curing, and subsequent application ofone or more successive thin layers containing a polymer of the formulaindicated hereinabove.

[0214]FIG. 3 is a similar view to that of FIG. 2 with a shallowanisotropically etched groove 40 in the heater plate, which is silicon,prior to formation of the underglaze 39 and patterning of the heatingelements 34, electrodes 33 and common return 35. This recess 40 permitsthe use of only the thick film insulative layer 18 and eliminates theneed for the usual electrode passivating layer 16. Since the thick filmlayer 18 is impervious to water and relatively thick (typically fromabout 20 to about 40 microns, although the thickness can be outside thisrange), contamination introduced into the circuitry will be much lessthan with only the relatively thin passivation layer 16 well known inthe art. The heater plate is a fairly hostile environment for integratedcircuits. Commercial ink generally entails a low attention to purity. Asa result, the active part of the heater plate will be at elevatedtemperature adjacent to a contaminated aqueous ink solution whichundoubtedly abounds with mobile ions. In addition, it is generallydesirable to run the heater plate at a voltage of from about 30 to about50 volts, so that there will be a substantial field present. Thus, thethick film insulative layer 18 provides improved protection for theactive devices and provides improved protection, resulting in longeroperating lifetime for the heater plate.

[0215] When a plurality of lower substrates 28 are produced from asingle silicon wafer, at a convenient point after the underglaze isdeposited, at least two alignment markings (not shown) preferably arephotolithographically produced at predetermined locations on the lowersubstrates 28 which make up the silicon wafer. These alignment markingsare used for alignment of the plurality of upper substrates 31containing the ink channels. The surface of the single sided wafercontaining the plurality of sets of heating elements is bonded to thesurface of the wafer containing the plurality of ink channel containingupper substrates subsequent to alignment.

[0216] As disclosed in U.S. Pat. Nos. 4,601,777 and 4,638,337, thedisclosures of each of which are totally incorporated herein byreference, the channel plate is formed from a two side polished, (100)silicon wafer to produce a plurality of upper substrates 31 for theprinthead. After the wafer is chemically cleaned, a pyrolytic CVDsilicon nitride layer (not shown) is deposited on both sides. Usingconventional photolithography, a via for fill hole 25 for each of theplurality of channel plates 31 and at least two vias for alignmentopenings (not shown) at predetermined locations are printed on one waferside. The silicon nitride is plasma etched off of the patterned viasrepresenting the fill holes and alignment openings. A potassiumhydroxide (KOH) anisotropic etch can be used to etch the fill holes andalignment openings. In this case, the [111] planes of the (100) wafertypically make an angle of about 54.7 degrees with the surface of thewafer. The fill holes are small square surface patterns, generally ofabout 20 mils (500 microns) per side, although the dimensions can beabove or below this value, and the alignment openings are from about 60to about 80 mils (1.5 to 3 millimeters) square, although the dimensionscan be outside this range. Thus, the alignment openings are etchedentirely through the 20 mil (0.5 millimeter) thick wafer, while the fillholes are etched to a terminating apex at about halfway through tothree-quarters through the wafer. The relatively small square fill holeis invariant to further size increase with continued etching so that theetching of the alignment openings and fill holes are not significantlytime constrained.

[0217] Next, the opposite side of the wafer is photolithographicallypatterned, using the previously etched alignment holes as a reference toform the relatively large rectangular recesses 24 and sets of elongated,parallel channel recesses that will eventually become the ink manifoldsand channels of the printheads. The surface 22 of the wafer containingthe manifold and channel recesses are portions of the original wafersurface (covered by a silicon nitride layer) on which an adhesive, suchas a thermosetting epoxy, will optionally be applied later for bondingit to the substrate containing the plurality of sets of heatingelements. The adhesive is applied in a manner such that it does not runor spread into the grooves or other recesses. The alignment markings canbe used with, for example, a vacuum chuck mask aligner to align thechannel wafer on the heating element and addressing electrode wafer. Thetwo wafers are accurately mated and can be tacked together by partialcuring of the adhesive.

[0218] Incorporation of the epoxy groups into the photopatternablepolyarylene ether enables or improves adhesion of the polyarylene etherlayer to the heater plate, and possibly also to the channel plate.Subsequent to imaging and during cure of the polyarylene ether, theepoxy groups react with the heater layer to form strong chemical bondswith that layer, improving adhesive strength and solvent resistance ofthe interface. The presence of the epoxy groups may also improve thehydrophilicity of the polyarylene ether and thus may improve the wettingproperties of the layer, thereby improving the refill characteristics ofthe printhead.

[0219] Alternatively, the heating element and channel wafers can begiven precisely diced edges and then manually or automatically alignedin a precision jig. Alignment can also be performed with an infraredaligner-bonder, with an infrared microscope using infrared opaquemarkings on each wafer to be aligned, or the like. The two wafers canthen be cured in an oven or laminator to bond them together permanently.The channel wafer can then be milled to produce individual uppersubstrates. A final dicing cut, which produces end face 29, opens oneend of the elongated groove 20 producing nozzles 27. The other ends ofthe channel groove 20 remain closed by end 21. However, the alignmentand bonding of the channel plate to the heater plate places the ends 21of channels 20 directly over elongated recess 38 in the thick filminsulative layer 18 as shown in FIG. 2 or directly above the recess 40as shown in FIG. 3 enabling the flow of ink into the channels from themanifold as depicted by arrows 23. The plurality of individualprintheads produced by the final dicing are bonded to the daughter boardand the printhead electrode terminals are wire bonded to the daughterboard electrodes.

[0220] In one embodiment, a heater wafer with a phosphosilicate glasslayer is spin coated with a solution of Z6020 adhesion promoter (0.01weight percent in 95 parts methanol and 5 parts water, Dow Corning) at3000 revolutions per minute for 10 seconds and dried at 100° C. forbetween 2 and 10 minutes. The wafer is then allowed to cool at 25° C.for 5 minutes before spin coating the photoresist containing thephotopatternable polymer onto the wafer at between 1,000 and 3,000revolutions per minute for between 30 and 60 seconds. The photoresistsolution is made by dissolving polyarylene ether ketone with from about1 to about 1.5 epoxy groups and from about 0.1 to about 1.0 chloromethylgroups per repeat unit and a number average molecular weight of fromabout 5,000 to about 7,000 (polydispersity ([M_(w)/M_(n)] of from about2 to about 5) in N-methylpyrrolidinone at 40 weight percent solids withMichler's ketone (1.2 parts ketone per every 10 parts of 40 weightpercent solids polymer solution). If desired, a curing agent, such asthe “Y” curative (meta-phenylenediamine) or the like, as well asmixtures thereof, can also be included in the photoresist solution. Thefilm is heated (soft baked) in an oven for between 10 and 15 minutes at70° C. After cooling to 25° C. over 5 minutes, the film is covered witha mask and exposed to 365 nanometer ultraviolet light, amounting tobetween 150 and 1,500 milliJoules per cm². The exposed wafer is thenheated at 70° C. for 2 minutes post exposure bake, followed by coolingto 25° C. over 5 minutes. The film is developed with any suitabledeveloper, such as 60:40 chloroform/cyclohexanone, mixtures ofcyclohexanone and methyl ethyl ketone, or the like, washed with 90:10hexanes/cyclohexanone, and then dried at 70° C. for 2 minutes. A seconddeveloper/wash cycle is carried out if necessary to obtain a wafer withclean features. The processed wafer is transferred to an oven at 25° C.,and the oven temperature is raised from 25 to 90° C. at 20° C. perminute. The temperature is maintained at 90° C. for 2 hours, and thenincreased to 260° C. at 2° C. per minute. The oven temperature ismaintained at 260° C. for 2 hours and then the oven is turned off andthe temperature is allowed to cool gradually to 250° C. When thermalcure of the photoresist films is carried out under inert atmosphere,such as nitrogen or one of the noble gases, such as argon, neon,krypton, xenon, or the like, there is markedly reduced oxidation of thedeveloped film and improved thermal and hydrolytic stability of theresultant devices. Moreover, adhesion of developed photoresist film isimproved to the underlying substrate. If a second layer is spin coatedover the first layer, the heat cure of the first developed layer can bestopped between 80 and 260° C. before the second layer is spin coatedonto the first layer. A second thicker layer is deposited by repeatingthe above procedure a second time. This process is intended to be aguide in that procedures can be outside the specified conditionsdepending on film thickness and photoresist molecular weight. Films at30 microns have been developed with clean features at 600 dots per inch.

[0221] For best results with respect to well-resolved features and highaspect ratios, photoresist compositions of the present invention arefree of particulates prior to coating onto substrates. In one preferredembodiment, the photoresist composition containing the photopatternablepolymer is subjected to filtration through a 2 micron nylon filter cloth(available from Tetko). The photoresist solution is filtered through thecloth under yellow light or in the dark as a solution containing fromabout 30 to about 60 percent by weight solids using compressed air (upto about 60 psi) and a pressure filtration funnel. No dilution of thephotoresist solution is required, and concentrations of an inhibitor(such as, for example, MEHQ) can be as low as, for example, 500 partsper million or less by weight without affecting shelf life. No build inmolecular weight of the photopatternable polymer is observed during thisfiltration process. While not being limited to any particular theory, itis believed that in some instances, such as those when unsaturated estergroups are present on the photopolymerizable polymer, compressed airyields results superior to those obtainable with inert atmospherebecause oxygen in the compressed air acts as an effective inhibitor forthe free radical polymerization of unsaturated ester groups such asacrylates and methacrylates.

[0222] In another embodiment, the photopatternable polymer is admixedwith an epoxy resin in relative amounts of from about 75 parts by weightphotopatternable polymer and about 25 parts by weight epoxy resin toabout 90 parts by weight photopatternable polymer and about 10 parts byweight epoxy resin. Examples of suitable epoxy resins include EPON1001F, available from Shell Chemical Company, Houston, Tex., believed tobe of the formula

[0223] and the like, as well as mixtures thereof. Curing agents such asthe “Y” curative (meta-phenylenediamine) and the like, as well asmixtures thereof, can be used to cure the epoxy resin at typicalrelative amounts of about 10 weight percent curative per gram of epoxyresin solids. Process conditions for the epoxy resin blended with thephotopatternable polymer are generally similar to those used to processthe photoresist without epoxy resin. Incorporation of the epoxy resininto the photopatternable polymer material improves the adhesion of thephotopatternable layer to the heater plate. Subsequent to imaging andduring cure of the photopatternable polymer, the epoxy reacts with theheater layer to form strong chemical bonds with that layer, improvingadhesive strength and solvent resistance of the interface. The presenceof the epoxy may also improve the hydrophilicity of the photopatternablepolymer and thus may improve the wetting properties of the layer,thereby improving the refill characteristics of the printhead.

[0224] The printhead illustrated in FIGS. 1 through 3 constitutes aspecific embodiment of the present invention. Any other suitableprinthead configuration comprising ink-bearing channels terminating innozzles on the printhead surface can also be employed with the materialsdisclosed herein to form a printhead of the present invention.

[0225] The present invention also encompasses printing processes withprintheads according to the present invention. One embodiment of thepresent invention is directed to an ink jet printing process whichcomprises (1) preparing an ink jet printhead comprising a plurality ofchannels, wherein the channels are capable of being filled with ink froman ink supply and wherein the channels terminate in nozzles on onesurface of the printhead, said preparation being according to theprocess of the present invention; (2) filling the channels with an ink;and (3) causing droplets of ink to be expelled from the nozzles onto areceiver sheet in an image pattern. A specific embodiment of thisprocess is directed to a thermal ink jet printing process, wherein thedroplets of ink are caused to be expelled from the nozzles by heatingselected channels in an image pattern. The droplets can be expelled ontoany suitable receiver sheet, such as fabric, plain paper such as Xerox®4024 or 4010, coated papers, transparency materials, or the like.

[0226] Specific embodiments of the invention will now be described indetail. These examples are intended to be illustrative, and theinvention is not limited to the materials, conditions, or processparameters set forth in these embodiments. All parts and percentages areby weight unless otherwise indicated.

EXAMPLE I

[0227] A polyarylene ether ketone of the formula

[0228] wherein n is between about 2 and about 30 (hereinafter referredto as poly(4-CPK-BPA)) was prepared as follows. A 5 liter, 3-neckround-bottom flask equipped with a Dean-Stark (Barrett) trap, condenser,mechanical stirrer, argon inlet, and stopper was situated in a siliconeoil bath. 4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich ChemicalCo., Milwaukee, Wis., 250 grams), bis-phenol A (Aldrich 23,965-8, 244.8grams), potassium carbonate (327.8 grams), anhydrousN,N-dimethylacetamide (1,500 milliliters), and toluene (275 milliliters)were added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component was collected and removed. After 48hours of heating at 175° C. with continuous stirring, the reactionmixture was filtered to remove insoluble salts, and the resultantsolution was added to methanol (5 gallons) to precipitate the polymer.The polymer was isolated by filtration, and the wet filter cake waswashed with water (3 gallons) and then with methanol (3 gallons). Theyield was 360 grams of vacuum dried product. The molecular weight of thepolymer was determined by gel permeation chromatography (gpc) (elutionsolvent was tetrahydrofuran) with the following results: M_(n) 3,601,M_(peak) 5,377, M_(w) 4,311, M_(z) 8,702, and M_(z+1) 12,951. The glasstransition temperature of the polymer was between 125 and 155° C. asdetermined using differential scanning calorimetry at a heating rate of20° C. per minute dependent on molecular weight. Solution cast filmsfrom methylene chloride were clear, tough, and flexible. As a result ofthe stoichiometries used in the reaction, it is believed that thispolymer had end groups derived from bis-phenol A.

EXAMPLE II

[0229] A solution of chloromethyl ether in methyl acetate was made byadding 282.68 grams (256 milliliters) of acetyl chloride to a mixture ofdimethoxy methane (313.6 grams, 366.8 milliliters) and methanol (10milliliters) in a 5 liter 3-neck round-bottom flask equipped with amechanical stirrer, argon inlet, reflux condenser, and addition funnel.The solution was diluted with 1,066.8 milliliters of1,1,2,2-tetrachloroethane and then tin tetrachloride (2.4 milliliters)was added via a gas-tight syringe along with 1,1,2,2-tetrachloroethane(133.2 milliliters) using an addition funnel. The reaction solution washeated to 500° C. Thereafter, a solution of poly(4-CPK-BPA) prepared asdescribed in Example I (160.8 grams) in 1,000 milliliters oftetrachloroethane was added rapidly. The reaction mixture was thenheated to reflux with an oil bath set at 110° C. After two hours refluxwith continuous stirring, heating was discontinued and the mixture wasallowed to cool to 25° C. The reaction mixture was transferred in stagesto a 2 liter round bottom flask and concentrated using a rotaryevaporator with gentle heating up to 50° C. while reduced pressure wasmaintained with a vacuum pump trapped with liquid nitrogen. Theconcentrate was added to methanol (4 gallons) to precipitate the polymerusing a Waring blender. The polymer was isolated by filtration andvacuum dried to yield 200 grams of poly(4-CPK-BPA) with 1.0 chloromethylgroups per repeat unit as identified using ¹H NMR spectroscopy.

EXAMPLE III

[0230] A 1-liter, 3-neck flask equipped with a mechanical stirrer, argoninlet, and addition funnel was charged with 175 milliliters of freshlydistilled tetrahydrofuran. Sodium hydride (6 grams), obtained fromAldrich Chemical Co., Milwaukee, Wis., was added, followed by additionof 2-allyl phenol (5 grams) dropwise, resulting in vigorous hydrogen gasevolution. Thereafter, a solution containing 5 grams of achloromethylated polyarylene ether ketone prepared as described inExample II in 50 milliliters of tetrahydrofuran was added. Stirring at25° C. was continued for 48 hours. The resulting polymer was filteredand the supernatant fluid was concentrated using a rotary evaporator.The concentrate was then added to methanol to precipitate the polymer,followed by in vacuo drying of the polymer.

[0231] The dried polymer (0.2 grams) in methylene chloride (100milliliters) was then treated with 1 gram of m-chloroperoxybenzoic acid(obtained from Aldrich Chemical Co., Milwaukee, Wis.) and magneticallystirred for 2 hours in a 200 milliliter bottle. The polymer was thenadded to saturated aqueous sodium bicarbonate (200 milliliters) and themethylene chloride was removed using a rotary evaporator. The resultingepoxidized polymer was filtered, washed with methanol (3 cups), andvacuum dried.

[0232] The epoxidized polymer in N-methyl pyrrolidinone (40 weightpercent polymer solids) was rendered photochemically active by theaddition of Irgacure 261 (obtained from Ciba-Geigy, Ardsley, N.Y.) tothe solution in an amount of 4 percent by weight of the polymer.Exposure to ultraviolet light, followed by heating to 70° C., anddevelopment with a cyclohexanone-methyl ethyl ketone mixture, yieldedmicrolithographic patterns. Subsequent thermal curing to 260° C.completely crosslinked the polymer, rendering it impervious to solventssuch as N-methylpyrrolidinone, methylene chloride, acetone, and hexanes.

EXAMPLE IV

[0233] The process of Example III was repeated with the exception that 5grams of allyl alcohol were used instead of the 2-allylphenol. Similarresults were obtained.

EXAMPLE V

[0234] A polyarylene ether ketone of the formula

[0235] wherein n is between about 6 and about 30 (hereinafter referredto as poly(4-CPK-BPA)) was prepared as follows. A 1 liter, 3-neckround-bottom flask equipped with a Dean-Stark (Barrett) trap, condenser,mechanical stirrer, argon inlet, and stopper was situated in a siliconeoil bath. 4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich ChemicalCo., Milwaukee, Wis., 53.90 grams), bis-phenol A (Aldrich 23,965-8,45.42 grams), potassium carbonate (65.56 grams), anhydrousN,N-dimethylacetamide (300 milliliters), and toluene (55 milliliters)were added to the flask and heated to 175° C. (oil bath temperature)while the volatile toluene component was collected and removed. After 24hours of heating at 175° C. with continuous stirring, the reactionmixture was filtered to remove potassium carbonate and precipitated intomethanol (2 gallons). The polymer (poly(4-CPK-BPA)) was isolated in 86%yield after filtration and drying in vacuo. GPC analysis was as follows:M_(n) 4,239, M_(peak) 9,164, M_(w) 10,238, M_(z) 18,195, and M_(z+1)25,916. Solution cast films from methylene chloride were clear, tough,and flexible. As a result of the stoichiometries used in the reaction,it is believed that this polymer had end groups derived from4,4-dichlorobenzophenone.

EXAMPLE VI

[0236] A polymer of the formula

[0237] wherein n represents the number of repeating monomer units wasprepared as follows. A 500 milliliter, 3-neck round-bottom flaskequipped with a Dean-Stark (Barrett) trap, condenser, mechanicalstirrer, argon inlet, and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 16.32 grams, 0.065 mol), bis(4-hydroxyphenyl)methane(Aldrich, 14.02 grams, 0.07 mol), potassium carbonate (21.41 grams),anhydrous N,N-dimethylacetamide (100 milliliters), and toluene (100milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 48 hours of heating at 175° C. with continuous stirring,the reaction mixture was filtered and added to methanol to precipitatethe polymer, which was collected by filtration, washed with water, andthen washed with methanol. The yield of vacuum dried product,poly(4-CPK-BPM), was 24 grams. The polymer dissolved on heating inN-methylpyrrolidinone, N,N-dimethylacetamide, and1,1,2,2-tetrachloroethane. The polymer remained soluble after thesolution had cooled to 25° C.

EXAMPLE VII

[0238] The polymer poly(4-CPK-BPM), prepared as described in Example VI,was chloromethylated as follows. A solution of chloromethyl methyl ether(6 mmol/milliliter) in methyl acetate was prepared by adding acetylchloride (35.3 grams) to a mixture of dimethoxymethane (45 milliliters)and methanol (1.25 milliliters). The solution was diluted with 150milliliters of 1,1,2,2-tetrachloroethane and then tin tetrachloride (0.3milliliters) was added. After taking the mixture to reflux using an oilbath set at 110° C., a solution of poly(4-CPK-BPM) (10 grams) in 125milliliters of 1,1,2,2-tetrachloroethane was added. Reflux wasmaintained for 2 hours and then 5 milliliters of methanol were added toquench the reaction. The reaction solution was added to 1 gallon ofmethanol using a Waring blender to precipitate the product,chloromethylated poly(4-CPK-BPM), which was collected by filtration andvacuum dried. The yield was 9.46 grams of poly(4-CPK-BPM) with 2chloromethyl groups per polymer repeat unit. The polymer had thefollowing structure:

EXAMPLE VIII

[0239] A polymer of the formula

[0240] wherein n represents the number of repeating monomer units wasprepared as follows. A 500 milliliter, 3-neck round-bottom flaskequipped with a Dean-Stark (Barrett) trap, condenser, mechanicalstirrer, argon inlet, and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich 11,370, Aldrich Chemical Co.,Milwaukee, Wis., 16.32 grams, 0.065 mol), hexafluorobisphenol A(Aldrich, 23.52 grams, 0.07 mol), potassium carbonate (21.41 grams),anhydrous N,N-dimethylacetamide (100 milliliters), and toluene (100milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 48 hours of heating at 175° C. with continuous stirring,the reaction mixture was filtered and added to methanol to precipitatethe polymer, which was collected by filtration, washed with water, andthen washed with methanol. The yield of vacuum dried product,poly(4-CPK-HFBPA), was 20 grams. The polymer was analyzed by gelpermeation chromatography (gpc) (elution solvent was tetrahydrofuran)with the following results: M_(n) 1,975, M_(peak) 2,281, M_(w) 3,588,and M_(z+1) 8,918.

EXAMPLE IX

[0241] The polymer poly(4-CPK-HFBPA), prepared as described in ExampleVIII, is chloromethylated by the process described in Example VII. It isbelieved that similar results will be obtained.

EXAMPLE X

[0242] A polymer of the formula

[0243] wherein n represents the number of repeating monomer units wasprepared as follows. A 1-liter, 3-neck round-bottom flask equipped witha Dean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Difluorobenzophenone (Aldrich Chemical Co., Milwaukee, Wis., 43.47grams, 0.1992 mol), 9,9′-bis(4-hydroxyphenyl)fluorenone (Ken Seika,Rumson, N.J., 75.06 grams, 0.2145 mol), potassium carbonate (65.56grams), anhydrous N,N-dimethylacetamide (300 milliliters), and toluene(52 milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 5 hours of heating at 175° C. with continuous stirring,the reaction mixture was allowed to cool to 25° C. The solidified masswas treated with acetic acid (vinegar) and extracted with methylenechloride, filtered, and added to methanol to precipitate the polymer,which was collected by filtration, washed with water, and then washedwith methanol. The yield of vacuum dried product, poly(4-FPK-FBPA), was71.7 grams. The polymer was analyzed by gel permeation chromatography(gpc) (elution solvent was tetrahydrofuran) with the following results:M_(n) 59,100, M_(peak) 144,000, M_(w) 136,100, M_(z) 211,350, andM_(z+1) 286,100.

EXAMPLE XI

[0244] A polymer of the formula

[0245] wherein n represents the number of repeating monomer units wasprepared as follows. A 1-liter, 3-neck round-bottom flask equipped witha Dean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Dichlorobenzophenone (Aldrich Chemical Co., Milwaukee, Wis., 50.02grams, 0.1992 mol), 9,9′-bis(4-hydroxyphenyl)fluorenone (Ken Seika,Rumson, N.J., 75.04 grams, 0.2145 mol), potassium carbonate (65.56grams), anhydrous N,N-dimethylacetamide (300 milliliters), and toluene(52 milliliters) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 24 hours of heating at 175° C. with continuous stirring,the reaction mixture was allowed to cool to 25° C. The reaction mixturewas filtered and added to methanol to precipitate the polymer, which wascollected by filtration, washed with water, and then washed withmethanol. The yield of vacuum dried product, poly(4-CPK-FBP), was 60grams.

EXAMPLE XII

[0246] The polymer poly(4-CPK-FBP), prepared as described in Example XI,was chloromethylated as follows. A solution of chloromethyl methyl ether(6 mmol/milliliter) in methyl acetate was prepared by adding acetylchloride (38.8 grams) to a mixture of dimethoxymethane (45 milliliters)and methanol (1.25 milliliters). The solution was diluted with 100milliliters of 1,1,2,2-tetrachloroethane and then tin tetrachloride (0.5milliliters) was added in 50 milliliters of 1,1,2,2-tetrachloroethane.After taking the mixture to reflux using an oil bath set at 100° C., asolution of poly(4-CPK-FBP) (10 grams) in 125 milliliters of1,1,2,2-tetrachloroethane was added. The reaction temperature wasmaintained at 100° C. for 1 hour and then 5 milliliters of methanol wereadded to quench the reaction. The reaction solution was added to 1gallon of methanol using a Waring blender to precipitate the product,chloromethylated poly(4-CPK-FBP), which was collected by filtration andvacuum dried. The yield was 9.5 grams of poly(4-CPK-FBP) with 1.5chloromethyl groups per polymer repeat unit. When the reaction wascarried out at 110° C. (oil bath set temperature), the polymer gelledwithin 80 minutes. The polymer had the following structure:

EXAMPLE XIII

[0247] A polymer of the formula

[0248] wherein n represents the number of repeating monomer units wasprepared as follows. A 1-liter, 3-neck round-bottom flask equipped witha Dean-Stark (Barrett) trap, condenser, mechanical stirrer, argon inlet,and stopper was situated in a silicone oil bath.4,4′-Difluorobenzophenone (Aldrich Chemical Co., Milwaukee, Wis., 16.59grams), bisphenol A (Aldrich 14.18 grams, 0.065 mol), potassiumcarbonate (21.6 grams), anhydrous N,N-dimethylacetamide (100milliliters), and toluene (30 milliliters) were added to the flask andheated to 175° C. (oil bath temperature) while the volatile toluenecomponent was collected and removed. After 4 hours of heating at 175° C.with continuous stirring, the reaction mixture was allowed to cool to25° C. The solidified mass was treated with acetic acid (vinegar) andextracted with methylene chloride, filtered, and added to methanol toprecipitate the polymer, which was collected by filtration, washed withwater, and then washed with methanol. The yield of vacuum dried product,poly(4-FPK-BPA), was 12.22 grams. The polymer was analyzed by gelpermeation chromatography (gpc) (elution solvent was tetrahydrofuran)with the following results: M_(n) 5,158, M_(peak) 15,080, M_(w) 17,260,and M_(z+1) 39,287. To obtain a lower molecular weight, the reaction canbe repeated with a 15 mol % offset in stoichiometry.

EXAMPLE XIV

[0249] 4′-Methylbenzoyl-2,4-dichlorobenzene, of the formula

[0250] was prepared as follows. To a 2-liter flask equipped with amechanical stirrer, argon inlet, Dean Stark trap, condenser, and stopperand situated in an oil bath was added toluene (152 grams). The oil bathtemperature was raised to 130° C. and 12.5 grams of toluene wereremoved. There was no indication of water. The flask was removed fromthe oil bath and allowed to cool to 25° C. 2,4-Dichlorobenzoyl chloride(0.683 mol, 143 grams) was added to form a solution. Thereafter,anhydrous aluminum chloride (0.8175 mol, 109 grams) was addedportion-wise over 15 minutes with vigorous gas evolution of hydrochloricacid as determined by odor. The solution turned orange-yellow and thenred. The reaction was stirred for 16 hours under argon, and on removingthe solvent, a solid lump was obtained. The mass was extracted withmethylene chloride (1 liter), which was then dried over potassiumcarbonate and filtered. The filtrate was concentrated using a rotaryevaporator and a vacuum pump to yield an oil which, upon cooling, becamea solid crystalline mass. Recrystallization from methanol (1 liter) at−15° C. gave 82.3 grams of 4′-methylbenzoyl-2,4-dichlorobenzene (meltingpoint 55-56° C.) in the first crop, 32 grams of product (from 500milliliters of methanol) in the second crop, and 16.2 grams of productin the third crop. The total recovered product was 134.7 grams in 65.6%yield.

EXAMPLE XV

[0251] Benzoyl-2,4-dichlorobenzene, of the formula

[0252] was prepared as follows. To a 2-liter flask equipped with amechanical stirrer, argon inlet, Dean Stark trap, condenser, stopper andsituated in an oil bath was added benzene (200 grams). The oil bathtemperature was raised to 100° C. and 19 grams of benzene were removed.There was no indication of water. The flask was removed from the oilbath and allowed to cool to 25° C. 2,4-Dichlorobenzoyl chloride (0.683mol, 143 grams) was added to form a solution. Thereafter, anhydrousaluminum chloride (0.8175 mol, 109 grams) was added portion-wise over 15minutes with vigorous gas evolution. Large volumes of hydrochloric acidwere evolved as determined by odor. The solution turned orange-yellowand then red. The reaction was stirred for 16 hours under argon and wasthen added to 1 liter of ice water in a 2-liter beaker. The mixture wasstirred until it became white and was then extracted with methylenechloride (1 liter). The methylene chloride layer was dried over sodiumbicarbonate and filtered. The filtrate was concentrated using a rotaryevaporator and a vacuum pump to yield an oil which, upon cooling, becamea solid crystalline mass (154.8 grams). Recrystallization from methanolgave 133.8 grams of benzoyl-2,4-dichlorobenzene as white needles(melting point 41-43° C.) in the first crop.

EXAMPLE XVI

[0253] 2,5-Dichlorobenzoyl chloride was prepared as follows. To a2-liter, 3-neck round-bottom flask situated in an ice bath and equippedwith an argon inlet, condenser, and mechanical stirrer was added2,5-dichlorobenzoic acid (93.1 grams) in 400 milliliters ofdichloromethane to form a slurry. Thionyl chloride (85 grams) in 68grams of dichloromethane was then added and the mixture was stirred at25° C. The mixture was then gradually heated and maintained at refluxfor 16 hours. Thionyl chloride was subsequently removed using a Claisendistillation take-off head with heating to greater than 80° C. Thereaction residue was transferred to a 500 milliliter 1-neck round bottomflask and then distilled using a Kugelrohr apparatus and a vacuum pumpat between 70 and 100° C. at 0.1 to 0.3 mm mercury to obtain 82.1 gramsof 2,5-dichlorobenzoyl chloride, trapped with ice bath cooling as ayellow-white solid.

EXAMPLE XVII

[0254] Benzoyl-2,5-dichlorobenzene, of the formula

[0255] was prepared as follows. To a 2-liter flask equipped with amechanical stirrer, argon inlet, Dean Stark trap, condenser, and stopperand situated in an oil bath was added benzene (140 grams). The oil bathtemperature was raised to 100° C. and 19 grams of benzene were removed.There was no indication of water. The flask was removed from the oilbath and allowed to cool to 25° C. 2,5-Dichlorobenzoyl chloride (92.6grams), prepared as described in Example XIX, was added to form asolution. Thereafter, anhydrous aluminum chloride (0.8175 mol, 109grams) was cautiously added portion-wise over 15 minutes with vigorousgas evolution. Large volumes of hydrochloric acid were evolved asdetermined by odor. The solution turned orange-yellow and then red. Thereaction was stirred for 16 hours under argon and was then added to 1liter of ice water in a 2-liter beaker. The mixture was stirred until itbecame white and was then extracted with methylene chloride (1 liter).The methylene chloride layer was dried over sodium bicarbonate andfiltered. The filtrate was concentrated using a rotary evaporator and avacuum pump to yield crystals (103.2 grams). Recrystallization frommethanol gave benzoyl-2,5-dichlorobenzene as white needles (meltingpoint 85-87° C.).

EXAMPLE XVIII

[0256] 4′-Methylbenzoyl-2,5-dichlorobenzene, of the formula

[0257] was prepared as follows. To a 2-liter flask equipped with amechanical stirrer, argon inlet, Dean Stark trap, condenser, and stopperand situated in an oil bath was added toluene (200 grams). Thereafter,anhydrous aluminum chloride (64 grams) was cautiously added portion-wiseover 15 minutes with vigorous gas evolution. Large volumes ofhydrochloric acid were evolved as determined by odor. The solutionturned orange-yellow and then red. The reaction was stirred for 16 hoursunder argon and was then added to 1 liter of ice water in a 2-literbeaker. The mixture was stirred until it became white and was thenextracted with methylene chloride (1 liter). The methylene chloridelayer was dried over sodium bicarbonate and filtered. The filtrate wasconcentrated using a rotary evaporator and a vacuum pump to yieldcrystals. Recrystallization from methanol gave 37.6 grams of4′-methylbenzoyl-2,5-dichlorobenzene as light-yellow needles (meltingpoint 107-108° C.).

EXAMPLE XIX

[0258] A polymer of the formula

[0259] wherein n represents the number of repeating monomer units wasprepared as follows. A 250 milliliter, 3-neck round-bottom flaskequipped with a Dean-Stark (Barrett) trap, condenser, mechanicalstirrer, argon inlet, and stopper was situated in a silicone oil bath.4′-Methylbenzoyl-2,4-dichlorobenzene (0.0325 mol, 8.6125 grams, preparedas described in Example XIV), bis-phenol A (Aldrich 23,965-8, 0.035 mol,7.99 grams), potassium carbonate (10.7 grams), anhydrousN,N-dimethylacetamide (60 milliliters), and toluene (60 milliliters,49.1 grams) were added to the flask and heated to 175° C. (oil bathtemperature) while the volatile toluene component was collected andremoved. After 24 hours of heating at 175° C. with continuous stirring,the reaction product was filtered and the filtrate was added to methanolto precipitate the polymer. The wet polymer cake was isolated byfiltration, washed with water, then washed with methanol, and thereaftervacuum dried. The polymer (7.70 grams, 48% yield) was analyzed by gelpermeation chromatography (gpc) (elution solvent was tetrahydrofuran)with the following results: M_(n) 1,898, M_(peak) 2,154, M_(w) 2,470,M_(z) 3,220, and M_(z+1) 4,095.

EXAMPLE XX

[0260] A polymer of the formula

[0261] wherein n represents the number of repeating monomer units wasprepared by repeating the process of Example XIX except that the4′-methylbenzoyl-2,4-dichlorobenzene starting material was replaced with8.16 grams (0.0325 mol) of benzoyl-2,4-dichlorobenzene, prepared asdescribed in Example XV, and the oil bath was heated to 170° C. for 24hours.

EXAMPLE XXI

[0262] The process of Example III is repeated except that thepoly(4-CPK-BPA) is replaced with the polymer prepared as described inExample XIX. It is believed that similar results will be obtained.

EXAMPLE XXII

[0263] The process of Example III is repeated except that thepoly(4-CPK-BPA) is replaced with the polymer prepared as described inExample XX. It is believed that similar results will be obtained.

EXAMPLE XXIII

[0264] The process of Example IV is repeated except that thepoly(4-CPK-BPA) is replaced with the polymer prepared as described inExample XIX. It is believed that similar results will be obtained.

EXAMPLE XXIV

[0265] The process of Example IV is repeated except that thepoly(4-CPK-BPA) is replaced with the polymer prepared as described inExample XX. It is believed that similar results will be obtained.

[0266] Other embodiments and modifications of the present invention mayoccur to those skilled in the art subsequent to a review of theinformation presented herein; these embodiments and modifications, aswell as equivalents thereof, are also included within the scope of thisinvention.

What is claimed is:
 1. A composition which comprises a polymercontaining at least some monomer repeat units withphotosensitivity-imparting substituents which enable crosslinking orchain extension of the polymer upon exposure to actinic radiation, saidpolymer being of the formula

wherein x is an integer of 0 or 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, wherein said photosensitivity-impartingsubstituents are allyl ether groups, epoxy groups, or mixtures thereof.2. A composition according to claim 1 further containing a sensitizer.3. A composition according to claim 1 further containing aphotoinitiator.
 4. A composition according to claim 1 further containinga solvent.
 5. A process which comprises the steps of (a) providing acomposition according to claim 1; and (b) causing the polymer to becomecrosslinked or chain extended through the photosensitivity-impartinggroups.
 6. A process according to claim 5 wherein crosslinking or chainextension is effected by heating the polymer to a temperature sufficientto enable the photosensitivity-imparting groups to form crosslinks orchain extensions in the polymer.
 7. A process according to claim 5wherein crosslinking or chain extension is effected by exposing thepolymer to actinic radiation such that the polymer in exposed areasbecomes crosslinked or chain extended.
 8. A process according to claim 7wherein the composition is exposed in an imagewise pattern such that thepolymer in exposed areas becomes crosslinked or chain extended and thepolymer in unexposed areas does not become crosslinked or chainextended, and wherein subsequent to exposure, the polymer in theunexposed areas is removed from the crosslinked or chain extendedpolymer, thereby forming an image pattern.
 9. A process according toclaim 8 further comprising the steps of: (a) depositing a layercomprising the polymer-containing composition onto a lower substrate inwhich one surface thereof has an array of heating elements andaddressing electrodes having terminal ends formed thereon, said polymerbeing deposited onto the surface having the heating elements andaddressing electrodes thereon; (b) exposing the layer to actinicradiation in an imagewise pattern such that the polymer in exposed areasbecomes crosslinked or chain extended and the polymer in unexposed areasdoes not become crosslinked or chain extended, wherein the unexposedareas correspond to areas of the lower substrate having thereon theheating elements and the terminal ends of the addressing electrodes; (c)removing the polymer from the unexposed areas, thereby forming recessesin the layer, said recesses exposing the heating elements and theterminal ends of the addressing electrodes; (d) providing an uppersubstrate with a set of parallel grooves for subsequent use as inkchannels and a recess for subsequent use as a manifold, the groovesbeing open at one end for serving as droplet emitting nozzles; and (e)aligning, mating, and bonding the upper and lower substrates together toform a printhead with the grooves in the upper substrate being alignedwith the heating elements in the lower substrate to form dropletemitting nozzles, thereby forming a thermal ink jet printhead.
 10. Aprocess which comprises reacting a polymer containing at least somemonomer repeat units with haloalkyl substituents thereon and of theformula

wherein x is an integer of 0 or 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, with an allyl alcohol salt, thereby forming aphotopatternable polymer with allyl ether functional groupscorresponding to the selected salt.
 11. A polymer prepared by theprocess of claim
 10. 12. A process according to claim 10 comprising thefurther step of reacting the polymer with allyl ether functional groupswith a peroxide, thereby forming a photopatternable polymer with epoxyfunctional groups.
 13. A polymer prepared by the process of claim 12.14. A composition which comprises a crosslinked or chain extendedpolymer of the formula

wherein x is an integer of 0 or 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, said crosslinking or chain extension occurringthrough photosensitivity-imparting substituents contained on at leastsome of the monomer repeat units of the polymer which form crosslinks orchain extensions in the polymer upon exposure to actinic radiation,wherein the photosensitivity-imparting substituents are allyl ethergroups or epoxy groups.
 15. An ink jet printhead which comprises (i) anupper substrate with a set of parallel grooves for subsequent use as inkchannels and a recess for subsequent use as a manifold, the groovesbeing open at one end for serving as droplet emitting nozzles, (ii) alower substrate in which one surface thereof has an array of heatingelements and addressing electrodes formed thereon, and (iii) a layerdeposited on the surface of the lower substrate and over the heatingelements and addressing electrodes and patterned to form recessestherethrough to expose the heating elements and terminal ends of theaddressing electrodes, the upper and lower substrates being aligned,mated, and bonded together to form the printhead with the grooves in theupper substrate being aligned with the heating elements in the lowersubstrate to form droplet emitting nozzles, said layer comprising acrosslinked or chain extended polymer-containing composition accordingto claim
 14. 16. A composition which comprises a crosslinked or chainextended polymer of the formula

wherein x is an integer of 0 or 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, said crosslinking or chain extension occurringthrough linking groups formed by a reaction between epoxy groupscontained on at least some of the monomer repeat units of the polymerand an amine curing agent.
 17. An ink jet printhead which comprises (i)an upper substrate with a set of parallel grooves for subsequent use asink channels and a recess for subsequent use as a manifold, the groovesbeing open at one end for serving as droplet emitting nozzles, (ii) alower substrate in which one surface thereof has an array of heatingelements and addressing electrodes formed thereon, and (iii) a layerdeposited on the surface of the lower substrate and over the heatingelements and addressing electrodes and patterned to form recessestherethrough to expose the heating elements and terminal ends of theaddressing electrodes, the upper and lower substrates being aligned,mated, and bonded together to form the printhead with the grooves in theupper substrate being aligned with the heating elements in the lowersubstrate to form droplet emitting nozzles, said layer comprising acrosslinked or chain extended polymer-containing composition accordingto claim
 16. 18. A process according to claim 10 further comprising thestep of causing the polymer to become crosslinked or chain extendedthrough the photosensitivity-imparting groups.
 19. A process accordingto claim 18 wherein crosslinking or chain extension is effected byheating the polymer to a temperature sufficient to enable thephotosensitivity-imparting groups to form crosslinks or chain extensionsin the polymer.
 20. A process according to claim 18 wherein crosslinkingor chain extension is effected by exposing the polymer to actinicradiation such that the polymer in exposed areas becomes crosslinked orchain extended.
 21. A process according to claim 20 wherein the polymeris exposed in an imagewise pattern such that the polymer in exposedareas becomes crosslinked or chain extended and the polymer in unexposedareas does not become crosslinked or chain extended, and whereinsubsequent to exposure, the polymer in the unexposed areas is removedfrom the crosslinked or chain extended polymer, thereby forming an imagepattern.
 22. A process according to claim 21 further comprising thesteps of: (a) depositing a layer comprising the polymer onto a lowersubstrate in which one surface thereof has an array of heating elementsand addressing electrodes having terminal ends formed thereon, saidpolymer being deposited onto the surface having the heating elements andaddressing electrodes thereon; (b) exposing the layer to actinicradiation in an imagewise pattern such that the polymer in exposed areasbecomes crosslinked or chain extended and the polymer in unexposed areasdoes not become crosslinked or chain extended, wherein the unexposedareas correspond to areas of the lower substrate having thereon theheating elements and the terminal ends of the addressing electrodes; (c)removing the polymer from the unexposed areas, thereby forming recessesin the layer, said recesses exposing the heating elements and theterminal ends of the addressing electrodes; (d) providing an uppersubstrate with a set of parallel grooves for subsequent use as inkchannels and a recess for subsequent use as a manifold, the groovesbeing open at one end for serving as droplet emitting nozzles; and (e)aligning, mating, and bonding the upper and lower substrates together toform a printhead with the grooves in the upper substrate being alignedwith the heating elements in the lower substrate to form dropletemitting nozzles, thereby forming a thermal ink jet printhead.
 23. Aprocess according to claim 10 further comprising the step of causing thepolymer to become crosslinked or chain extended through thephotosensitivity-imparting groups.
 24. A process according to claim 23wherein crosslinking or chain extension is effected by heating thepolymer to a temperature sufficient to enable thephotosensitivity-imparting groups to form crosslinks or chain extensionsin the polymer.
 25. A process according to claim 23 wherein crosslinkingor chain extension is effected by exposing the polymer to actinicradiation such that the polymer in exposed areas becomes crosslinked orchain extended.
 26. A process according to claim 25 wherein the polymeris exposed in an imagewise pattern such that the polymer in exposedareas becomes crosslinked or chain extended and the polymer in unexposedareas does not become crosslinked or chain extended, and whereinsubsequent to exposure, the polymer in the unexposed areas is removedfrom the crosslinked or chain extended polymer, thereby forming an imagepattern.
 27. A process according to claim 26 further comprising thesteps of: (a) depositing a layer comprising the polymer onto a lowersubstrate in which one surface thereof has an array of heating elementsand addressing electrodes having terminal ends formed thereon, saidpolymer being deposited onto the surface having the heating elements andaddressing electrodes thereon; (b) exposing the layer to actinicradiation in an imagewise pattern such that the polymer in exposed areasbecomes crosslinked or chain extended and the polymer in unexposed areasdoes not become crosslinked or chain extended, wherein the unexposedareas correspond to areas of the lower substrate having thereon theheating elements and the terminal ends of the addressing electrodes; (c)removing the polymer from the unexposed areas, thereby forming recessesin the layer, said recesses exposing the heating elements and theterminal ends of the addressing electrodes; (d) providing an uppersubstrate with a set of parallel grooves for subsequent use as inkchannels and a recess for subsequent use as a manifold, the groovesbeing open at one end for serving as droplet emitting nozzles; and (e)aligning, mating, and bonding the upper and lower substrates together toform a printhead with the grooves in the upper substrate being alignedwith the heating elements in the lower substrate to form dropletemitting nozzles, thereby forming a thermal ink jet printhead.
 28. Acomposition according to claim 1 wherein A is

and B is

wherein z is an integer of from 2 to about 20, or a mixture thereof. 29.A process according to claim 5 wherein A is

and B is

wherein z is an integer of from 2 to about 20, or a mixture thereof. 30.A process according to claim 10 wherein A is

and B is

wherein z is an integer of from 2 to about 20, or a mixture thereof. 31.A process according to claim 12 wherein A is

and B is

wherein z is an integer of from 2 to about 20, or a mixture thereof. 32.A composition according to claim 14 wherein A is

and B is

wherein z is an integer of from 2 to about 20, or a mixture thereof. 33.A composition according to claim 16 wherein A is

and B is

wherein z is an integer of from 2 to about 20, or a mixture thereof. 34.A composition according to claim 1 wherein the polymer has end groupsderived from the “A” groups of the polymer.
 35. A composition accordingto claim 1 wherein the polymer has end groups derived from the “B”groups of the polymer.
 36. A process according to claim 5 wherein thepolymer has end groups derived from the “A” groups of the polymer.
 37. Aprocess according to claim 5 wherein the polymer has end groups derivedfrom the “B” groups of the polymer.
 38. A process according to claim 10wherein the polymer has end groups derived from the “A” groups of thepolymer.
 39. A process according to claim 10 wherein the polymer has endgroups derived from the “B” groups of the polymer.
 40. A processaccording to claim 12 wherein the polymer has end groups derived fromthe “A” groups of the polymer.
 41. A process according to claim 12wherein the polymer has end groups derived from the “B” groups of thepolymer.
 42. A composition according to claim 14 wherein the polymer hasend groups derived from the “A” groups of the polymer.
 43. A compositionaccording to claim 14 wherein the polymer has end groups derived fromthe “B” groups of the polymer.
 44. A composition according to claim 16wherein the polymer has end groups derived from the “A” groups of thepolymer.
 45. A composition according to claim 16 wherein the polymer hasend groups derived from the “B” groups of the polymer.
 46. A processaccording to claim 5 wherein prior to crosslinking or chain extensionthe polymer is admixed with a solvent to form a solution containing fromabout 30 to about 60 percent by weight of the polymer, followed byfiltration of the solution through a 2 micron nylon filter cloth underpositive pressure.
 47. A process which comprises reacting a polymercontaining at least some monomer repeat units with haloalkylsubstituents thereon and of the formula

wherein x is an integer of 0 or 1, A is

or mixtures thereof, B is

wherein v is an integer of from 1 to about 20,

wherein z is an integer of from 2 to about 20,

wherein u is an integer of from 1 to about 20,

wherein w is an integer of from 1 to about 20,

or mixtures thereof, and n is an integer representing the number ofrepeating monomer units, with an epoxy-group-containing alcohol salt,thereby forming a photopatternable polymer with epoxy functional groupscorresponding to the selected salt.
 48. A polymer prepared according tothe process of claim
 47. 49. A process according to claim 47 furthercomprising the step of causing the polymer to become crosslinked orchain extended through the photosensitivity-imparting groups.
 50. Aprocess according to claim 49 wherein crosslinking or chain extension iseffected by heating the polymer to a temperature sufficient to enablethe photosensitivity-imparting groups to form crosslinks or chainextensions in the polymer.
 51. A process according to claim 49 whereincrosslinking or chain extension is effected by exposing the polymer toactinic radiation such that the polymer in exposed areas becomescrosslinked or chain extended.
 52. A process according to claim 51wherein the polymer is exposed in an imagewise pattern such that thepolymer in exposed areas becomes crosslinked or chain extended and thepolymer in unexposed areas does not become crosslinked or chainextended, and wherein subsequent to exposure, the polymer in theunexposed areas is removed from the crosslinked or chain extendedpolymer, thereby forming an image pattern.
 53. A process according toclaim 52 further comprising the steps of: (a) depositing a layercomprising the polymer onto a lower substrate in which one surfacethereof has an array of heating elements and addressing electrodeshaving terminal ends formed thereon, said polymer being deposited ontothe surface having the heating elements and addressing electrodesthereon; (b) exposing the layer to actinic radiation in an imagewisepattern such that the polymer in exposed areas becomes crosslinked orchain extended and the polymer in unexposed areas does not becomecrosslinked or chain extended, wherein the unexposed areas correspond toareas of the lower substrate having thereon the heating elements and theterminal ends of the addressing electrodes; (c) removing the polymerfrom the unexposed areas, thereby forming recesses in the layer, saidrecesses exposing the heating elements and the terminal ends of theaddressing electrodes; (d) providing an upper substrate with a set ofparallel grooves for subsequent use as ink channels and a recess forsubsequent use as a manifold, the grooves being open at one end forserving as droplet emitting nozzles; and (e) aligning, mating, andbonding the upper and lower substrates together to form a printhead withthe grooves in the upper substrate being aligned with the heatingelements in the lower substrate to form droplet emitting nozzles,thereby forming a thermal ink jet printhead.
 54. A process according toclaim 47 wherein A is

and B is

wherein z is an integer of from 2 to about 20, or a mixture thereof. 55.A process according to claim 47 wherein the polymer has end groupsderived from the “A” groups of the polymer.
 56. A composition accordingto claim 47 wherein the polymer has end groups derived from the “B”groups of the polymer.